Invasive Plants in Permaculture

A couple of months ago, I posted on this site an article that reviewed three garden shows, noting that the third of these, the Ecological Landscaping Association’s Annual Conference, gave its attendees a thought-provoking paradox. One of the event’s speakers discussed the vast and costly damage caused by Japanese knotweed in Great Britain, and another illustrated the nearly hopeless job of managing invasive plants on public lands in Massachusetts.

Hardy kiwi: a big player in edible landscaping

Kiwi escaped and on the loose in western Massachusetts

Ironically, the closing keynote speaker, Ben Falk, touted a brand of gardening – generally termed permaculture – which, in contrast to its many sensible practices, also recommends using plants that can spread far and fast if left untended, disrupting regional ecosystems, i.e. plants that are generally called invasive. The example I used was hardy kiwi: a staple of many permaculture plans, this vine has  now thoroughly swallowed up large swaths of once-healthy forest in southern New England and the Midwest. I pointed out the odd contradiction between the movement’s lofty goals and this one clearly harmful practice.

In response to my post, Mr. Falk wrote a lengthy tirade against my “native fundamentalist” misconceptions, in which he extolled the many virtues of modern permaculture, and derided my out-dated “Nativistic War-On-Alien-Invader ideology.”

The ELA posted this lecture in their monthly newsletter, calling it a rebuttal to my piece. Falk’s article did not actually rebut my concerns about the use of invasive plants in permaculture, and instead simply denied the entire concept of invasiveness, but his claims could not be further discussed, since the ELA site allows no comments.

Enter, a few weeks later, Katharine Gehron and Jenna Webster. Both are graduates of the Conway School of Landscape Design (as is Ben Falk), and both are additionally trained in permaculture. Hoping to clarify the issues, Gehron and Webster wrote a thoughtful response to Falk’s article, and asked the ELA to print this too in their newsletter. ELA decided instead to post the article as a pdf in their LinkedIn discussion group where, it must be noted, only group members are likely to see it.

So, to give this informative article the exposure it deserves, here it is again…on an open site that does allow all civil comments. I hope that readers of this blog will also forward this post to friends and colleagues who are involved in permaculture, to get a full range of responses. I myself have also commented on this subject, in a post in this blog entitled “Permaculture’s Internal Contradiction.”



by Katharine Gehron & Jenna Webster

In “Measuring Progress: Permaculture Responds,” Ben Falk defends permaculture on many fronts without ever directly responding to Sue Reed’s specific critique of a single, yet common, permacultural practice: the use of nonnative species that are or may prove to be invasive. In our estimation, Falk’s response rhetorically sidesteps this important issue, and we feel compelled to write in support of Reed’s argument. While we recognize that permaculture has much to offer society (we have both taken permaculture classes—one of us has obtained certification—and we have both toured permaculture gardens and homesteads, including Whole Systems Research Farm in Moretown, VT, with Falk himself), we could not agree more with Reed on this issue.

Reed writes, “[Permaculturists] promote using several . . . .invasive plants [in addition to hardy kiwi], including autumn olive . . . and oriental bittersweet. . . . What about native plants and insects? What about harm to native ecosystems?”

Japanese stiltgrass eliminates all forest floor diversity.

Same for Japanese pachysandra, but what matters is not where the plant comes from, nor how long it has been here. What matters is the plant’s depauperating effect on once-diverse ecosystems.

Falk’s response never acknowledges that such plants have come under scrutiny by many reputable ecologists and environmental advocates for their ability to damage local ecosystem health. Instead, without offering any scientific evidence to back up his position, Falk invalidates this line of criticism by using language such as “Nativistic War-on-Alien-Invader ideology” and suggesting that such an ideology exists solely because some people have a sentimental, irrational bias for North American ecosystems prior to European settlement. He dismissively equates native-plant advocacy with simple nostalgia, stating, “Attempts to maintain . . . an unchanging romantic notion of species assemblage are currently retarding real progress toward enhancing the health of living systems on planet Earth.” This representation severely distorts the position of native-plant advocates. Most of the time, such a generalization is incorrect and a diversion from the discussion.


In his defense of permacultural use of nonnative species, Falk distorts commonly held, scientifically based precepts: “[Permaculture] does not, in general, see plants or other organisms that have been in a place for 10 or 100 or 300 years as fundamentally more ‘natural’ or proper in a place than plants which are recent arrivals.” This is a defensible position only if the person holding it is also prepared to argue that the drastic simplifications in ecological communities which sometimes result from such migrations or introductions are justifiable. We feel that by misrepresenting and ignoring scientific evidence about the workings of ecology and evolution, Falk weakens the credibility of his and his peers’ admirable enterprise to provide food and other human essentials more sustainably.

So, what do scientific studies tell us?

Many native fauna are unable to complete their life cycle with nonnative plants.

Noted entomologist Douglas Tallamy published Bringing Nature Home in 2007 to share with gardeners the results of his studies on the ability of native insects to utilize nonnative plants to support their life cycle. For the fate of biodiversity and the protection of local species, his results are not encouraging. In just one study of insect herbivores found eating woody native and nonnative species, the native vegetation supplied four times more insect biomass simply because the insects’ chewing mouthparts were unable to process alien plants (328). Accordingly, when fewer native insects are available to native birds evolved to eat particular insect species and to feed them to their young, bird populations may also decline (63).

Native fauna have coevolved with native plants over millions of years; accordingly, they are adapted to use native plants throughout their life cycle.

As Tallamy notes in a discussion of humans’ overeagerness to consider a plant “at home” when it is convenient to people, plants have coevolved over millions of years with other species in the places where they live, both influencing and being influenced by the changes in the life forms around them (66). Evolution works at a time scale exponentially slower than the pace of change that humans have caused in just a few generations. Species simply cannot evolve fast enough to adapt to and use many of the plants they have not coevolved with. (We recognize that even within the category of plants we call “native,” there is considerable variation in understanding what that term means, but we will leave these finer distinctions aside for purposes of our argument here.)

Native flora have also coevolved, checking each other’s growth. Nonnatives often have no such checks on the size of their population.

When a plant is introduced to a part of the world where it has never lived before, in many cases the forces that kept the plant in check are suddenly removed, as are the complex and longstanding ecological relationships created by coevolution (Tallamy 66). It’s true that some native species, such as poison ivy and Canada goldenrod, can be aggressively opportunistic and behave like nonnative invasives in certain situations. However, it’s important to remember that many of our native species can use these plants to sustain themselves and their young, unlike the situation with many nonnatives.

The proliferation of nonnative invasives or aggressive native generalist species can be a sign that human activity has disrupted a balance. To the best of our ability, we should mitigate the causes of such disruption. But this obligation does not relieve us of the duty to prevent the introduction of nonnative invasives. As David Jacke points out in Edible Forest Gardens (2005), “Natives may be more likely than nonatives to have unintended benefits, and less likely to have unintended negative consequences.” (vol. 1, 159).

The unchecked spread of nonnatives can be devastating to local ecosystems.

Permaculturists who claim to create complex, thriving, biodiverse landscapes paint an appealing picture, one that is an often beautiful and accurate reflection of their accomplishments, but such language obscures the great harm that can result when certain practitioners plant and advocate for the planting of species with the ability to spread far beyond one person’s garden or farm. Such plants can overwhelm local plant communities, often on a massive scale, replacing diverse assemblages of coevolved species with biologically unstable near monocultures. The consequences of these conversions—besides the increased use of herbicides and the need for ever-greater management efforts from already overtaxed farmers, municipalities, conservation agencies, and other land stewards—include, among other things, the alteration of hydrological cycles and water quality, changes in wildfire frequencies and intensities, and the degradation of aquatic habitats as a result of soil erosion (Tallamy, 85).

Even if a nonnative plant does not demonstrate invasive tendencies now, that does not mean it will not do so in the future.

Falk observes, as have other permaculturists, that humans have been moving plants and animals for thousands of years. This is certainly true, but it does not equate that past anthropogenic plant dispersal, intentional or not, absolves us from exercising extreme caution when introducing plants for human benefit. This is especially true when we consider present-day ecosystems, which are experiencing profound stresses, from climate change to acid rain to habitat fragmentation, on orders of magnitude unknown thousands of years ago. Such stresses have made many of today’s landscapes more susceptible to domination by plant species removed from their original contexts, and from the ecological constraints imposed by those contexts. In fact, as ecologist Steven Apfelbaum noted in his book Nature’s Second Chance: Restoring the Ecology of Stone Prairie Farm (2009), nonnative plants that do not currently appear to have invasive tendencies may well prove invasive in the future due to human-induced changes in soils, climate, hydrology, and/or other conditions (180-81).


Finally, on related note, we would like to address what we feel to be an inappropriate parallel Falk draws between the spread of humans and the diversity of human cultures, and the spread of plant species. He writes, “ In [Sue Reed’s] vision of a ‘native’ world, would she like to see all but the first (indigenous) peoples removed from the ecosystem in which they have artificially been introduced – including us Europeans in North America?” Surely, we would all agree that our success in building a more respectful, diverse, multicultural society is to be much lauded. However, Falk’s article would seem to suggest that permaculture is helping to make the world more ecologically “cosmopolitan” faster, and that this is as good and right as our multicultural global society. Yet human multiculturalism is not analogous to the introduction of alien plant species. Arguments linking the structure of human society with the mechanisms of the natural world have been made before, and in ways that have proved deeply problematic. We feel that such comparisons should be done with the greatest of caution, as they often serve to further ideological goals and are frequently without basis in scientific evidence.

While we wish to thank Falk and other devoted permaculture practitioners for taking on the difficult work of helping build the foundation for localized, non-corporate, environmentally sustainable systems designed to provide food, energy, medicine, materials, and other essentials, we believe—like Sue Reed—that the evidence about the negative effects of invasive species is too important to ignore.

Katharine Gehron holds a master’s degree from the Conway School, a graduate program in sustainable landscape planning and design. Her professional experience includes land-use consulting, green cemetery advocacy, and sustainable residential landscape design. She will be attending the Yale School of Forestry and Environmental Studies in the fall to pursue a master’s degree in environmental science.

Jenna Webster is a designer with Larry Weaner Landscape Associates (LWLA). At LWLA she has been involved with master plans for small and large residential and public projects, in addition to helping plan and implement educational programs for LWLA’s affiliate, New Directions in the American Landscape. Prior to joining LWLA she received a master’s degree from the Conway School, a graduate program in sustainable landscape planning and design, and worked for Natural Landscapes Nursery (a wholesale native plant nursery) as well as land preservation agencies in southeast Pennsylvania.


© 2012 – 2013, Sue Reed. All rights reserved. This article is the property of Native Plants and Wildlife Gardens. We have received many requests to reprint our work. Our policy is that you are free to use a short excerpt which must give proper credit to the author, and must include a link back to the original post on our site. Please use the contact form above if you have any questions.

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  1. Carole says

    Currently, denying science seems to be quite acceptable. It’s going to get us into a heap of trouble and I’m afraid in some instances it will be too late to turn back. Very disheartening.

  2. says

    Yes, there does seem to be a strange movement underway….not exactly denying science altogether, but choosing selected bits and pieces of science to use as justification for actions that would normally be considered harmful, and claiming that the other science is either wrong, biased or just old-fashioned foolishness. At the very least we, we must keep raising questions.

    • says

      It all boils down to how we define the problem, and permaculture proponents seem to be defining it differently than native plant advocates do. In their formulation, apparently, the entire concept of “invasiveness” doesn’t exist. Very odd.

  3. says

    I strongly disagree with Falk, for all the reasons mentioned. I feel his arguments ignore the science, and permaculture needs to evolve with respect to invasive species. Thank you for printing the rebuttal.
    Linda recently posted..June Bloom Day

    • says

      I’m sure Mr. Falk doesn’t speak for the entire permaculture movement (despite the title of his article), and in fact some of his colleagues might be pretty chagrined by his ranting tone and wild accusations, but his commentary does inspire a careful examination of the issues.

  4. Mark says

    I would point out that one of the 12 principles of Permaculture is to value diversity. When a non-native (or even a native) plant is allowed to become invasive, or rather, to monopolize the resources of an environmental niche, it is cause for concern, since it violates that principle. In these situations, it is important to heed another Permaculture principle, that of observing and interacting with one’s environment.

    The situation described in this article only goes to show that Permaculture is complex mix of twelve interrelated principles, and that its practice is an ongoing process. It’s practitioners should not allow themselves to become enthralled by the dogmatic pursuit of any one element of the design. To do so would only serve to repeat the mistakes of the monoculture agriculture of our industrialized food production system. I would suggest that one goal should be to create an environment, and a diversity of plants and other elements, that allows the system to coexist, benignly and productively, with a minimal amount of human input to correct such human-introduced imbalances.

    • says

      Mark, thank you for this thoughtful comment. I’m struck by how one of your sentences almost exactly replicates the statement I wrote that seems to have so enraged Mr. Falk, i.e. that by promoting the use of invasive plants, permaculture, “like the worst agriculture and horticulture systems in our past, still places human wishes and desires (often called needs) in the center of the equation.” I believe, and I think most native plant proponents would agree, that healthy functioning of the natural world should be our primary interest. Everything we do in our landscapes – including even food-production – should be done in service to that goal.

      • Mark says

        As a budding Permaculturist, I consider my that objective is to “organize” what nature delivers, so that I can make my best use of what nature already does. I suppose that at some point, nature has a purpose for what those “invasive” plants do for their environment. It is our obligation to discover that purpose, and to utilize it when we need it, including incorporating the”checks and balances” from nature to come up with an ethical whole. After all, the first Ethical Principle of Permaculture is “Care for the Earth”.

  5. says

    Excellent Sue!! Thank you too . . . for posting the letter from Katharine and Jenna. Permaculture has intrigued me for many years and I bought the first edition of the book with that title by . . . I cannot remember who. I agree with Mark’s comment above that the “Care for the Earth” is a most important principle. Having to deal with bitter-sweet vines on my land, I must say . . . that anyone who encourages its use is nearly criminal. It simply is toxic to native plants and trees!
    Carol Duke recently posted..Orange Unfurling Oriental Poppies and Baltimore Oriole

    • says

      I appreciate your feedback, Carol. One of the things that particularly worries me about permaculturists who don’t recognize the danger of invasive plants, is their assertion that they are controlling these plants on site, so there’s no chance of escape. Hm…. I’m skeptical.

      • Mark says

        Controlling plants onsite only works (and imperfectly at that) when there is someone around to do the controlling. And that requires extra work, extra input of human energy. As we have seen with the “escape” of Bio-engineered genes in plants, life has a way of “escaping” from any cage! I, too, am skeptical of the”escape-proof” cage.

  6. says

    Very important subject! It is odd how much we have in common with Ben Falk, for instance: “ecosystems (are) constantly evolving assemblages of species and shifting relationships between all pieces of the ecosystem”, “all members of a living system are connected”, “human and ecosystem health (are) mutually dependent”. That is why it is sad to see some peculiar discrepancies, such as talking about “the unchanging romantic notion of species assemblage”, “native-plant fundamentalists” or “Nativistic War-on-Alien-Invader ideology”. I see a severe misunderstanding of the issue of human introductions of organisms throughout the world.

    When reading his article on ELA I began to frame some answers in my mind, but fortunately Kate and Jenna took care of the main points magnificently.

    However, in case Ben reads this blog comments, I want to say this to him:

    Dear Ben:

    There is nothing sentimental, simplistic or ill informed about the efforts to preserve and restore native ecosystems, or at least to restore part of their functionality by removing non-natives or preventing the additional arrival of more non-natives. There is solid science behind it. Kate and Jenna gave you several references to substantiate the importance of well integrated ecosystems, those that have coevolved for more than just “10 or 100 or 300 years”. These numbers are trivial when one considers the length of time it takes for coevolved relationships to develop.

    When it comes to agriculture, we are well aware that most crops (perhaps more than 99%) are non-native, here as well as in all other continents. We are pragmatists and we are not about to give up our wheat, potatoes and rice or our beef and chicken. Asians and Europeans are not giving up potatoes or corn either. That is the way it is and we accept it.

    However, the countless instances of non-natives gone invasive and causing damage to the environment teach us to put an end to intentionally introducing and spreading more non-natives. It is my impression that many permaculturists agree with this notion.

    I want to remind you that an additional problem of non-native plants is that in some instances they carry hidden pests that cause them no serious problems because they are adapted to them. But when that same pest jumps to one of the natives, it can drive it to extinction or ecological functional extinction because of lack of coadaptation between plant and pest. Please, let us not repeat the mistakes of the past. It is bad enough with the American elm and American chestnut, and more recently the hemlock and several native viburnums.

    So, please, follow the best permaculture principles without neglecting the ecological principles of coevolved communities and their need to preserve their integrity.
    Beatriz Moisset recently posted..No Tree is an Island

    • says

      Hi Beatriz, and thanks so much for your clarifying comments. You and I think alike! In my first response (as yet unpublished) to Mr. Falk’s letter, I, too, noted the perfect overlap between the claims he makes for permaculture and the those same, long-held beliefs of all native-plant advocates.
      Also, I especially appreciate your reminder about the disruptive/destructive pests that often come along with non-native plant introductions, and your calm, respectful tone.

  7. jono neiger says

    Ill start by saying the idea that permaculture is a brand of gardening is so far off the mark as to make the rest of the arguments presented bunk.

    Its interesting to see the issue defined as native plant advocates or permaculturist. All the permaculture folks I know are very well versed in many plant communities and use many “native” plants. I was planting restoration sites with natives since in ’89. Probably before most on this comment section heard the word native or became strident on the issue. Seeing the world as black and white is classic- defining us and them, in or out, good or bad. Sounds like fundamentalism.

    I can get into more of the research that I’ve done which refutes much of the invasives rhetoric at some point (read Mark Davis- Invasion Biology if you’re serious on the issue). Gehron and Webster have based a chunk of their argument on Doug Tallamy’s work, which is amazing. Please go back and read the book. Please tell me where the credible research he presents is. As far as I can tell he has an appendix with some anectdotal “data” from his backyard. Sorry thats not “published” data. Its a good hypothesis looking for some data. I looked at a later study he actually got published (published in a peer review journal that is) comparing insects in a meadow vs an ornamental landscape. The meadow levels were higher; no surprise there.

    The idea of co-evolution is in flux to. Given that all species in the northeast were driven out by the glaciation only 15,000 years ago and returned at varying speeds, the idea of tightly interdependent co-evolved communities doesn’t hold much water. Some good published work by scientists at Harvard forest have looked at this and rebuked the notion of tightly co-evolved communities and the need for species to adapt to the changes of climate since the glacial retreat.

    There’s more and more scientists questioning the basic arguments for the intensive rhetoric of the invasives proponents. Look out, because science works over long time periods to dissolve poor ideas and scientific/cultural misconceptions. We will wake someday to realize its us and not the other new arrivals that are the problem.

    • says

      Hi Jono, and thanks for taking the time to comment. There’s a lot in your writing to respond to, but I guess I’ll just focus on your opening statement. Toby Hemenway (author of “Gaia’s Garden”) says that “permaculture is more like horticulture, or basically small-scale gardening, than agriculture.” This is a quote from a video lecture he gave, entitled “How Permaculture Can Save Humanity and The Planet – But Not Civilization,” which is posted on his website, He then goes on to describe all the ways that permaculture is a form of horticulture, and to praise that fact.

      I thought Hemenway was a pretty major spokesperson for, if not also one of the early thinkers about, the permaculture movement. Maybe I’m wrong about that. Or maybe you disagree with his comments, and that’s why you said calling permaculture a form of gardening is bunk.

      Anyway, this whole series of events in the last few months (since I wrote about the ELA conference) has really inspired me to learn more about permaculture. I still don’t understand why so many people who seem to be motivated by concern for the Earth wouldn’t have as their starting point an attitude of caution. I wonder: why act in ways that have any potential at all of causing harm, especially while at the same time stating that the science about invasive plants is in flux? But perhaps as I study and read more, and talk to more permaculture advocates, I’ll find some answers to this question.

      • says

        Oops, Jono, as I re-read your comment I realized you didn’t actually write that my calling permaculture “a form of gardening” is bunk. You said that it was so far off the mark. I apologize for the mis-statement. Still, this doesn’t really change the point I was trying to make.

    • Mark says

      I agree that Permaculturists often prefer using native plant guilds–primarily because they have already been shown to work well together–fewer potential problems, and less human work envolved to use groups of plants that already like being together.

      I especially agree with Jono’s statement that it is usthat is the problem: in the words of Pogo: “We have met the enemy, and he is us!”

    • says

      Dear Jono:

      I have been concerned about introduced plants and other organisms since the 60s and 70s when I saw the impact that firethorn and privet had on the ecosystems of my native land, Argentina. It is no consolation that the Argentinean ant and the nutria are having similar impact in this country. All these organisms do well in their native lands. It is another story when humans move them around.

      “Anecdotal data from his backyard”?, “credible research”?, “hypothesis looking for some data”? What are you talking about? Doug Tallamy and his collaborators have publications in journals as distinguished as “Conservation Biology”, “Biological Invasions” and “Ecosphere”.

      Please, read: “Non-native plants reduce abundance, richness, and host specialization in Lepidoptera communities” ( and “Impact of Native Plants on Bird and Butterfly Biodiversity in Suburban Landscapes” ( I invite you to pay special attention to the methodology and statistics; no “anecdotal data from his backyard” here.

      The latter article studied insect and bird biodiversity in two types of ornamental landscapes with comparable amounts of cover (lawn, shrubs and trees). The only difference was that some had been landscaped with mostly native plants; the others were traditional ones with predominance of non-natives. The ones rich in native plants had significantly higher numbers of insects (bird food) and of birds.

      As for the post-glaciation advance of plants and other organisms; entire communities moved north, yes, there were some sprinters and stragglers, but the process took thousands of years, giving time for fine tuning. How does that compare with the huge numbers of introductions that we, humans, have been doing specially in the last couple of generations from all corners of the world to all other corners? Communities simply don’t have time to adapt to so many changes.

      We seem to agree in many issues. We (meaning you and us) share a deep concern for the environment. We love and respect nature. We have given serious thought and study to the issues. We are alarmed at the many mistakes we, humans, have committed and want to repair some of the damage. The difference is in our visions of what is best for the environment. So, please, don’t be the first one to turn this discussion into an “us vs. them” schism.

      We can discuss these matters in an intelligent, respectful and friendly way. I am eager to learn about the research you have done. So, please, give us some references.

    • Kate Gehron says

      Thanks for your response, Jono. The point Jenna and I were making in our response to Ben Falk’s rejection of the concept of invasiveness was not that nonnative plants are always bad (quite the contrary, they are often very useful and benign), and we were careful to demonstrate that we do not feel there is any sweeping “us vs. them” component to this discussion. Our point, rather, was that the continued use of certain opportunistic, aggressive nonnative plants in permaculture (and elsewhere, though the discussion originated from Falk’s article entitled “Permaculture Responds”) seems to be unwise, in light of their known tendencies to spread prolifically.

      In Nature (vol. 474, 9 June 2011, 153-4), Mark Davis writes, “Today’s management approaches must recognize that the natural systems of the past are changing forever thanks to drivers such as climate change, nitrogen eutrophication, increased urbanization and other land-use changes.” Agreed. “It is time for scientists, land managers and policy-makers to ditch this preoccupation with the native–alien dichotomy and embrace more dynamic and pragmatic approaches to the conservation and management of species — approaches better suited to our fast-changing planet.” This may be entirely sensible. Davis does not, however, reject the notion that some introduced species are harmful: “We are not suggesting that conservationists abandon their efforts to mitigate serious problems caused by some introduced species, or that governments should stop trying to prevent potentially harmful species from entering their countries.”

      It is clear that many scientists are concerned that a lower level of concern about nonnative plant introduction may lead policy makers to abandon sensible caution; see, for example, the responses to Davis in Nature (vol. 475, 7 July 7 2011, 36), including “Non-natives: 141 scientists object.” What’s more, rethinking invasive management policy (responding to an existing situation) is an entirely different matter from planting known opportunistic species (contributing to a situation), especially when we are not certain that these prolific species are not causing harm.

      The scale of contemporary change, the type of change occuring, and its pace are not readily comparable to events in the past, and when the effects of our actions are uncertain, it seems that a conservative approach is simply wise. New theories alone are not sufficient reason to abandon caution on the part of those who choose which plants to put in the ground to serve human needs.

    • Jenna Webster says

      Dear Jono,

      Thanks for taking the time to comment. To follow up on Beatriz’s post regarding Tallamy’s work, I would add that Tallamy’s Bringing Nature Home (2009, 2nd ed.) was intended for a general audience and to imply is not “serious” like Mark Davis’s Invasion Biology (2009) is a mischaracterization of Bringing Nature Home and its intent. Tallamy, a well-respected entomologist, deliberately used a conversational tone and avoided an academic style in order to appeal to non-specialists—and indeed his book, perhaps more than any other in recent years, helped spark a national conversation about the future of biodiversity in North America. A lay style does not mean lack of peer-reviewed research here; indeed the peer-reviewed articles listed by Beatriz Moisset in her June 21 post (as well as others listed on Tallamy’s web site) directly informed the writing of Bringing Nature Home.

      You mentioned your research in your June 19 post and like Beatriz, I hope you will share it, particularly any work that is peer reviewed. I am familiar with your writings discussing the language often associated with invasive plants (for example, Ecological Landscaping Association newsletter, Feb. 15, 2011) and agree that the “intensive” language used to characterize certain plants and their traits can be problematic. Yet just because our use of language so far has proved inadequate or fraught, it does not mean the ecological, social, and economic harm that can result from willful introduction of non-native plants with known invasive tendencies is any less real or that we can be incautious in this regard.

      • jono neiger says

        Yes- I know that Tallamy’s book was written for a general audience. Unfortunately that audience believes that the work proves his hypothesis.In your writing you say

        “Noted entomologist Douglas Tallamy published Bringing Nature Home in 2007 to share with gardeners the results of his studies on the ability of native insects to utilize nonnative plants to support their life cycle.”

        I asked where in the book are the results of his studies? I looked in the literature for any studies by him. I found the one mentioned ” Impact of Native Plants on Bird and Butterfly Biodiversity in Suburban Landscapes” which compares 6 mowed grass landscapes and 6 diverse native planted landscapes and (lo and behold!) the diverse native landscapes support more insect diversity. Its good to do this- sometimes we need to prove the obvious- but it doesn’t prove newly arrived species dont support insect populations.

        I appreciate you bringing up the issue of harm. This is central. Economic harm is slippery. Because an industry needs to spend more doesn’t equate to ecological harm. Paying to restore an area could be considered harm from industry standpoint. Some consider aquatic plants harmful because they interfere with boating. Research shows these plants can support aquatic life. Its the fact that we dont want to swim or boat in places with all the messy plants. So we spray “harmless” chemicals in the water to kill them. Ecological harm has been harder for ecologists to prove. In some cases (islands and isolated populations) newly arrived species can push others out. But in other contexts its been harder to prove.

        Several published papers that I can reference right now might be of interest (got to head to work after all- sorry the references are incomplete but you should be able to find these)

        Tamarix as Habitat for Birds: Implications for Riparian Restoration in the Southwestern United States, Sogge et al.

        Viewing invasive species removal in a whole-ecosystem context, Zavaleta (less data here but a good

        Nobody is saying this is easy and clearcut. Its not black and white and thats difficult for some people. Finding species to blame is much easier for some than changing what we do and getting to the work of cleaning up our mess.

        • says

          Jono: I asked you to read the methodology carefully. You missed a basic point when you said:
          ‘I found the one mentioned “Impact of Native Plants on Bird and Butterfly Biodiversity in Suburban Landscapes” which compares 6 mowed grass landscapes and 6 diverse native planted landscapes.’
          The 6 pairs of gardens were matched by amount and diversity of plant cover, so they did not include “mowed-grass landscapes”. The abundance and variety of birds and Lepidoptera was larger in the native landscapes anyhow. Moreover, this is not the only study by Doug Tallamy’s group. There are about 6 closely pertinent to this discussion and maybe 60 or so that have some degree of connection with the notion that native plants provide food for herbivores.
          Beatriz Moisset recently posted..Pollinator Conservation Short Course

  8. says

    The ideas behind permaculture were first articulated in the 1970′s, by Australian Bill Mollison.They have undoubtedly evolved quite a bit since then, but I’ve been criticized for calling permaculture “a form of gardening,” and in response, I’d like to offer two quotes from Mr. Mollison himself, both taken from a 1991 interview conducted by the Context Institute, entitled “Permaculture: Design For Living.”

    Mollison speaking: People ask, “What’s your occupation?” I say, “I’m just a simple gardener.”
    And another: What can permaculture teach the Bushmen that the Bushmen wouldn’t already know? Gardening.

    I do understand that permaculture is a complex set of principles and practices. Yet based on these words from movement’s creator, calling it a form of gardening doesn’t seem so very far off the mark.

    If you want to read more, the interview is here:

    • says

      Hey Rebecca, thanks so much for posting this study! Very, very interesting results. It’s amazing how much our understanding keeps growing, the closer we look.

    • jono neiger says

      Even though I found the study simplistic (they mimicked wetlands in stock tanks and studied it for a summer) they even found results showing benefits of loosestrife. Unfortunately it wasn’t what they were looking for so they wrote it off quickly…

      From the article:
      “In an unexpected turn, flowering loosestrife actually increased zooplankton species richness, perhaps, speculates Smith, because they preferentially ate a dominant zooplankton species, releasing others from competition.
      “To be honest,” Smith says, “although the increase in zooplankton diversity is interesting and surprising, I don’t think that specific detail matters too much. Nor, is the point simply that purple loosestrife might be affecting aquatic ecosystems, although that is important from a management perspective.
      “What matters is that we showed the interconnections are actually strong enough to transmit disturbances through and across webs. We pushed on one link and something four links away in another ecosystem moved.”

  9. says

    Dear Sue et al,

    I’m hesitant to wade into this, since it’s such a hot-button issue, but I will. (One note: Sue, when I used the term “horticulture” in my lecture, I was careful to define it not as gardening, but as a type of society, like agricultural or industrial societies. You misunderstood me. A permacultural approach is akin to a that of horticultural society, which is not a society that raises prize roses, but one that has very different spiritual, cultural, and economic practices than ours. Permaculture started out as a type of food production, but it’s definitely not a form of gardening. It’s a design approach for regenerative problem-solving.)

    Invasion biology itself has been undergoing a major revision over the last 15 years or so as many of their scientists realize that much earlier research was biased, based on false assumptions, and often set out to prove what was assumed rather than letting raw data speak. Mark Davis’s book describes this, as does a recent article by native-plant advocate Dr. Dan Simberloff (Environmental Ethics (2012) 34:5). I also recommend David Theodoropoulous’s “Invasion Biology: Critique of a Pseudoscience” which has many scholarly references showing how little damage can be laid at invasives’ feet. Reviews of this book are at
    (my own, written to be perhaps a little too provocatively) and

    Googling “invasion biology controversy” yields a host of articles showing that “invasive” exotics turn out rarely to be the source of the problem. They are nearly always a symptom, of nature throwing a green band-aid over disturbance, usually caused by human development. The photo at the top of this blog, of hardy kiwi rampant, is not of an intact ecosystem being ravaged, but rather an unnatural human-caused edge chewed into a forest, where kiwi is one of many, like bittersweet, trying to create biomass and photosynthesis where we have destroyed it. This is a classic example of blaming a plant when it is not remotely the cause of the problem. It’s nature using what’s available to solve a problem.

    It turns out that there is not one case of an invasive plant causing extinction of another species. But lay people like many of the posters here are about 15 years behind the times, still believing the earlier biased propaganda (much of it promoted by herbicide makers) that there are “bad” species. Intact ecosystems are notoriously hard to invade, otherwise, with billions of birds dropping trillions of seeds all over the planet for millions of years, the earth would be a mass of kudzu. If you see an “invasive” species (“opportunist” is a far more scientific term, since they are not invasive in many habitats), it’s almost always a sign of disturbance. Of course there are exceptions–shade lovers like English ivy and kudzu can enter undisturbed forest. Of course there are species that can reduce diversity, cost us money, and smother a tree (the way native ficus does in the tropics). But mostly, not.

    Gehron and Webster rely almost exclusively on Tallamy’s generally excellent book for their facts, but Tallamy has really high-graded his data, as reviewers have pointed out. He had a point to prove. He ignores mountains of articles showing that many exotics, such as tamarisk and purple loosestrife, to choose just two out of hundreds, support the same numbers and diversity of native insects as the “native” plants nearby. Tallamy has selected ornamental exotics as his test cases, but these were deliberately chosen by nurseries, and prized by gardeners, specifically because they resist insect damage by being unpalatable. So to use these as examples of plants that don’t support local insects is biased, because you are proving that the plants do what they were chosen by us to do. A more fair selection of species shows that exotics in general create dozens of partnerships with local flora and fauna within a very short time. Out of the thousands that do that, we focus on the handful, like kudzu, that don’t, and tar all exotics with the same brush. Our highway departments imported hundreds of species, planted by the hundreds of thousands, and indeed, a handful of species like Russian olive escaped because birds love the seeds and it’s a great soil-builder (as is kudzu). Russian olive is trying to turn your lawn back into the forest, via a shrub-succession step, that it wants to be under the irrigation you’re giving it. An examination of many “invasives” shows that nearly all are playing similar roles of healing. It looks ugly to us, as in the photo above, but when we cut a hole into a forest, exposing shade-loving trees to light and thus harming them, it is wrong to blame kiwi for “choking” these now-disadvantaged trees. Kiwi is just the fastest to thrive in the new, changed conditions.

    This is a very nuanced discussion and requires far more words that this to cover intelligently. I suggest that anyone who still believes that it’s as simple as “natives good, exotics bad” or who has plants they love to hate do some more research, and look for the evidence on the other side, as any good scientist would. If you want to look a little deeper, another article at my website goes into this a bit more.
    Thanks for the very flame-free discussion.

    • says

      Thank you very much, Mr. Hemenway, for your thoughtful response and detailed explanation of your perspective. I really do appreciate it. My apologies if I misunderstood your use of the term “horticulture.” However, I have heard many, many permaculturists use the term “gardening” for what they do, including Mr. Ben Falk, whose original highly-emotional tirade against me and all native plant advocates triggered this conversation.

      I agree with you that this subject seems almost impossibly complex. But I would like to respond briefly to your point about “nature” using hardy kiwi to heal disturbance. I can see how this seems true, but it is also true that if hardy kiwi weren’t available to be used, the healing process might include a much wider range of local plants, perhaps growing a bit more slowly and in more inter-connected relationships than happens when species as aggressive, disruptive and/or opportunistic (take your pick as to the right term) as hardy kiwi are present. And the result might then be a multi-layered and richly complex new ecosystem instead of the solid blanket of vines, which “nature” must now overcome to create more “healing.”

      Given what you have written here, as elsewhere, I suspect that my own comments on this subject (which appear at will not influence your thoughts in any way. I would just point out, as I do in that post, that “extinction” is not the focus of most native plant advocates’ concern. Rather, our concern is invasive species’ impact on biodiversity. Even Mark Davis warns us about this reality, in a passage that I quote in my post. I invite you to take at look at it, if you wish, and respond to the questions that I raise there about what I perceive to be the real issues: human carelessness and the impact of our mistakes.

  10. says

    Thank you Toby, for your thoughtful and comprehensive look at natives vs non natives in your article:

    These two sentences from that article really sum things up for me:
    “Unwanted species generally arrive because humans have changed the environment to make conditions more favorable for the new species.
    “To remove an unwanted species, change the conditions that made it more favored than the desired vegetation.”

    These two thoughts could be considered maxims on the subject – they offer very simple and workable truths which open the door to implementing solutions.

    If we really care about ecosystems, we need to get down to fundamental causes of their degradation and disruption. Non-native opportunists (I also prefer that word to “invasives”) are a symptom, not a cause.

    Native plant lovers and permaculturists both care about the environment and want to preserve and enhance our natural resources. I will bet that if we focus on getting to root causes of these disturbances (and Toby gives several good examples in his article), we will find many ways to work together to address real causes, instead of arguing with each other about it.

    The phrase “divide and conquer” comes to mind. Who benefits from people who care about the environment arguing with each other instead of focusing on those creating by far the most damage – monocrop agriculturists, and industrialists? I have seen this phenomena happen, over and over, where rather than working together to focus on the situations and individuals causing the most harm, two groups with similar goals take each other to task.

    I appreciate Toby’s differentiation of urban gardening with exotics, and large scale agriculture. Too often, the adverse effects of large scale agriculture don’t ever come into the natives vs non-native discussion.

    As Toby said, we are not going to solve the problem of invasives by stopping people from planting them. Invasives are only there because of the opportunities our human systems give them – this doesn’t get fully addressed by stopping the sale or distribution of non-native opportunists. I do support the control of certain opportunists, for instance, Causarina in the Everglades in Florida. But at the same time, we need to look at what stress that ecosystem is under from outside sources, and address that. And a continued study of all aspects of causarina’s effects – good and bad – should occur.

    Why not look for win-win solutions, using the “needs” of the system that created the problem, to solve the problems? This is something permaculture is known for. For instance, kudzu gets its hold from edges created by humans. You see it all along our highway systems that cut through forests in SE United States. Kudzu also has at least 22 economically valuable uses. It makes great animal fodder (high in protein) for one thing. So, why not farm the edges of freeways, which will enable us to let some fields go fallow and return to native species, or at least not monocropped? You do not need fertilizer or other inputs to grow kudzu. And there are thousands of acres of it in production! This is application of the permaculture principle – “the problem is the solution.”

    An idea from Dan Hemenway:

    Per my observation, kudzu does not penetrate very far into intact, stable ecosystems, it gains its opportunity from disturbed edges. Those freeway edges are unlikely to go away any time soon. So let’s use that problem to solve another one – the use of many, many acres of fields to grow monocrop feed for animals.

    As a permaculturist, I feel that one can’t observe systems closely or long enough – there is always something more to learn. I think that most of us, regardless of which “camp” we are in, feel the same way. It’s vital to understand the root causes of the aggressive growth of a new species in a system. An imbalance exists – what caused it? Is that the most primary, fundamental cause that we can isolate? Let’s take an even closer look and make sure. If we’ve found it, then how can THAT be remedied?

    Permaculture principles facilitate creation of win-win solutions that address multiple problems with elegantly simple solutions. It would be too bad if the power of permaculture design was overlooked or dismissed because of syntax or misunderstandings of what we are trying to accomplish. Of course, like native plant specialists, permaculturists come in all shapes and sizes and levels of experience and knowledge. We are all in learning stages, wherever in that process we may be. I appreciate the efforts to respectfully educate and share knowledge on this topic – we can all be richer, for it.

    • says

      Thank you, Koreen, for your comments. It is clear, as I’ve written elsewhere, that the permaculture way of thinking is creative and full of good ideas. Apart from our differing perspectives on the role of humans and the possible value of non-native aggressive/opportunisitic plants that are here now and can’t be eradicated, I continue to be mystified by the very same point that has mystified me from the start. And so far no one has really addressed this simple question: How dare permaculturists introduce MORE problems for nature and us humans to overcome, heal, compensate for or whatever you call it, by freely planting and promoting MORE non-native, aggressive/opportunistic species? I guess if I try to see these plants as somehow nature’s only way to heal the problems humans have caused, as Toby Hemenway posits, then it sort of makes a little bit of sense. But I do have a hard time accepting that these plants are the ONLY tools nature has available, in this work, simply because humans have disturbed things so much we give nature no choice. Even if my way of thinking is 15 years behind the times, as he suggests, this new way of thinking is really very hard to swallow. I hope you will take a moment to read more about my perspective on this issue at:

      • says

        I did read the article. Sue, have you had personal experience with permaculturists planting invasives and having them then take over a previously intact ecosystem? Can you share specifics on exactly what happened? I am trying to understand the specific problem you are trying to solve here.
        Koreen Brennan recently posted..Our new name – Grow Permaculture!

        • says

          Koreen: I cannot answer your specific question; but I can answer it in more general terms.
          There are numerous examples of plants that become invasive after years of being “well behaved”, or the pests they carry jump to native plants and become invasive. There is a lag time between introduction and invasion, which can be short or long. So, at the present time we don’t know which of the many non-natives are ticking bombs. Why should we be playing this Russian roulette? In many cases we aggravate the situation by introducing the non-native, again and again, into other areas. Among the many examples of what I mention are: the American chestnut blight, the Dutch elm disease, the hemlock woolly adelgid, and more recently the viburnum leaf beetle. All of them were introduced with horticultural stock. All of them are causing damage to originally healthy habitats. And then there is the Japanese beetle, which also arrived with plants. That one seems to do well in gardens and farms rather than intact ecosystems.
          How can we predict which ones will become invasive down the road with our unwitting help? Wouldn’t it be better never to find out?
          Beatriz Moisset recently posted..Pollinator Conservation Short Course

          • says

            I think the paradigms described in the book 1491 turn this type of thinking on its head. Indigenous people spread corn and related plants throughout the Americas, burned large swaths of land repeatedly, traded seed over large areas in some cases, and yet, the ecosystems thrived. Those aggressively managed ecosystems are what we are now trying to preserve by leaving them totally alone, which is not going to happen. Nothing remains in stasis in nature yet that is what it sounds like you are suggesting. It is also not real to expect that we are not going to bring in new pests. Some are brought in shipping containers or whatever. The trees in my backyard woods, the Los Angeles Crest National Forest became vulnerable to disease vectors and bugs because of other man made stressors, like pollution.

            The world is so very interrelated. The answer of permaculturists is to get to know the natural world intimately, to become a part of it, to love it, to live in it and continue to take care of it; and meanwhile to bring elements back into destroyed and degraded landscapes which include the full panoply found in healthy ecosystems from the bacteria and fungi to the canopy trees. I appreciate the discussions about “what is native” because what comes out of those is that almost no one agrees on that. I just had a native plant specialist tell me that mango trees were considered native in S Florida because the Indians brought them a few hundreds years ago. Where is the line drawn?

            We could discuss that point for a long time I am sure. But I would much rather focus on the points where we do agree. I use native plants wherever possible in the landscape, and I use plants that are established in the area otherwise and are not known as invasives. I’m not importing strange plants from Guam or the deep jungles of Brazil. I don’t know any permaculturist who does that. I love natives and try to find new ways to incorporate them, and I learn about new ones, regularly. Permaculturists work with nature so of course they would use the plants that are indigenously growing and doing well in that area. You did not address Toby’s very relevant point about monocropping and the damage that does. We are converting monocrop farms, in some cases, to small polycrop farms that have wildlife corridors and native pollinators. We are planting trees in cities and growing our food locally which keeps all that petroleum pollution off the wildlife corridors near freeways. One of my students has a big garden and food forest sprinkled with native pollinators and installed a beautiful native pollinator corridor along the edge by the sidewalk. Many people visit the site and learn about the natives, in the context of their own gardens. Is this not a positive thing?

            So, what do we have in common? Is there a common ground where we could work together to take care of the natural world that we both obviously love?

            Koreen Brennan recently posted..Our new name – Grow Permaculture!

  11. says

    Bill Mollison teaches several rules about planting: First, stay out of the bush (don’t mess in wild places). Then, always chose a native first if it will do the job. If not, a tested exotic. And only then, small trials of untested exotics. I’ve never known a permaculturist to do that last, because there are so many thousands of plants in the first two categories. No permaculturist plants Russian olive willy-nilly in the wild; that’s a silly myth. We work in damaged lands (usually already full of exotics), small farms, and backyards. All of these lands are far from wild, and only the first has any chance of being wild again, and we’re helping it get there faster than the native restorationists. Yes, I may plant a Russian olive in a suburban yard, although the highway commission planted 2 million of them nearby and they are now blacklisted and swarming over the disturbed, logged, once-farmed, developed, overgrazed, no longer naturally burned landscape. Really, one more in a yard is a problem? Their ability to build that yard’s soil and wildlife habitat, I will wager, outweighs any damage of a bird carrying a seed into the neighbor’s acre of exotic Kentucky bluegrass where it will be killed by his lawn mover. That’s the most damage a permaculturist will ever do. I think the “evil permaculturist destroying healthy ecosystems” is a complete myth. It’s more productive to go after a timber company or Cargill than your allies if you want to stop the spread of exotics.

    We have the same goals as nativists: preserve and restore ecosystem health, minimize human footprint. Most restoration projects fail, and permaculturists are looking for more successful strategies than “spray, plant the native, and pray.” Those projects show a poor grasp of ecology. They fail because the conditions that once supported the natives are gone. I want them to succeed. So we try to restore the conditions first, and plant the natives later, via scaffold plants that disappear over time. I’ve done this on large acreages, seen Scot’s broom and Himilayan blackberry take over a clearcut, build the soil and nurture young native trees much faster than in the surrounding native meadow, and then die out when the trees shade them. It’s ugly during that transition (though the wildlife loves it), and our puny 80-year lifespan doesn’t grasp ecosystem timeframes, but the result is a functioning ecosystem far more robust than a bunch of pines stuck into herbicided soil. Our methods work better at restoring ecosystems. I’ve seen it. And there is irony in a nativist with a yard full of non-endangered natives, thinking they are restoring land while they eat their granola, commissioning wild prairie conversion into Monsanto-land. Their breakfast does more damage than my Russian olive.

    Nature never says, “a functioning ecosystem can only contain these species.” She works by function, not by species. To answer Sue’s question, before kiwi or bittersweet arrived, a forest clearing (in New England) was first filled by bramble and poison ivy. Are those really superior to bittersweet or kiwi when those latter produce more biomass, take out the damaged sun-intolerant species faster to let edge species move in, and offer good food to wildlife? The only argument is that the exotics need 50 or 500 years to develop the alliances that the natives have, and they will (many exotics do this very quickly). But to say, “Nature is wrong to use kiwi over bramble, we’re going to make her use bramble, dammit!” presupposes a wisdom that we don’t have. Why, then, does nature favor the exotics now? Could they be better at doing the jobs nature needs? Why do they move in, really? Permaculture is based on observation, and when I see a vigorous hybrid ecosystem developing, one that keeps returning no matter how often you spray it, I have to think nature is onto something. I can no longer think, “Stupid nature, bramble belongs there.” I don’t think there are evil, murderous plants that must be killed.Nature is using whatever is available to restore plant cover, take out disadvantaged species that can’t deal with the new conditions, and bring in missing functions like biomass accumulation, soil building and retention, air purification, and all the rest. We just don’t like that it looks different from the way it used to.

    If we had an animated vegetation map of any area over the last 1000 years or so, we’d see a seething mass of change. The idea that there is an ideal ecosystem made of specific species, and no other will do, is not based in science, but in prejudice. Humans are naturally born xenophobes: We hate outsiders. I think in many cases it’s that simple. For example, Douglas fir, the signature Northwest native, came from (they think) Arizona about 4000 years ago, drove out the prairie plants except where Indians burned them, and was a horrible invasive exotic for centuries. Now it is fully implicated and loved. Same with Pacific madrone, one of the greatest wildlife species and land-healers around, which probably rafted up from South America. All “native” means is that it was here when a botanist first arrived. Doug fir is horribly invasive—it is destroying the last prairie remnants since they are no longer burned—but we don’t call it that because it is native. That’s where invasion biology becomes pseudoscience. They’ll say, if it’s a native nitrogen fixer, it is building soil, but an exotic N-fixer is branded a disruptive soil ecology disturber. That’s bias. We need to look at the plant’s function and understand what it is doing there.

    What this subject needs is a set of cohesive essays that unpacks the issues in a logical order, instead of the shot-gun spray that I’m doing here. Maybe I’ll work on that.

    One final thought: permaculture is full of former native-plant maniacs like Jono and me who found permaculture’s approach more sound and successful than that of the restorationists at healing damaged ecosystems. I’ve never met a permaculturist who abandoned their exotic-using to return to natives only. It’s a one way flow. Maybe there’s a good reason.

    • says

      Thanks again, Toby, for your detailed explanations. I can’t possibly respond to all the points you raise. I look forward to reading your cohesive essays on this subject, I really do. And I hope will they include a fair exploration of the studies that continue to confirm the impact of introduced species on biodiversity (which even Mark Davis says is a concern). We native plant supporters may be 15 years behind the times, as you say. I can accept that possibility. I will read the studies presented by the commenter below, and I will keep my mind open. But at this point I am not willing to act in ways that even MIGHT cause harm, as I understand harm. To my mind, that is a chance I’m just not going to take, even if it might make my life easier.

    • Jenna Webster says

      Thank you, Toby Hemenway and others, for your contributions. It’s helpful to hear from a prominent practitioner who directly engages Sue Reed’s original question regarding the intentional introduction of non-native plants with the potential to disrupt the biodiversity of existing ecosystems. While recent posts have been interesting and although I myself have taken permaculture classes and use nonnative plants in my own gardens and to a lesser extent in my professional practice, I remain unconvinced by arguments in Hemenway’s and similar posts.

      I understand fully well that we live amidst emergent ecologies of native and non-native flora and fauna. Yet when science doesn’t offer definitive answers about these ecologies, I believe it’s one thing to try to understand how to interact with these emergent systems and that it’s quite another thing to deliberately plant and advocate invasive/aggressive/opportunistic nonnative species in order to fulfill one’s ideas about what humans require or what one believes “nature” needs.

      A few additional thoughts:

      Hemenway’s analogy of poison ivy (Toxicodendron radicans) and bramble (Rubus spp.) in a New England forest gap pre-Euro-American settlement to a contemporary gap of bittersweet (Celastrus orbiculatus) and hardy kiwi (Actinidia arguta) seems like a self-serving oversimplification. New England forest gaps, depending on the situation, did not historically consist first of just one species (poison ivy) and one genus (brambles) but a shifting mosaic of grasses, forbs, ferns, and pioneer trees, shrubs, and vines. (For those who’re interested, vegetative cover reconstructions and animated maps of pollen distributions in North America since the last glacial maximum are available online.) To reduce all forest gaps to a poison ivy-bramble association in order to equate them with contemporary gaps of bittersweet and hardy kiwi distorts past situations, presumably in order to justify cultural use of species like hardy kiwi.

      Battling the destructive practices of industry and corporations (a point raised by Hemenway) is undeniably important but so are reasoned discussions among practitioners about complex issues; such discussions help advance the rigor of what we are trying to do and the many scales at which we do it. Moreover, in my understanding, this current discussion has never been about using natives exclusively (as some posts seem to have assumed it to be); nor has the point of the discussion ever been to imply we can somehow return to an imagined idyllic world before our design. To suggest this, whether through a misinterpretation of the discussion or to inflame that discussion, distorts the topic at hand and does us all a disservice.

  12. says

    One more thought: I now how upsetting it must be to go out and and pull or spray a bunch of autumn olive, and then have Ben Falk or whoever say it’s not a problem. But we have several accusations here of permaculturists causing harm by planting a few invasive species in yards, and let’s look at that.

    I would like to see these people present some evidence that permaculturists have significantly, even to a tiny extent, contributed to ecological damage.

    I think we have a false syllogism going on here:
    1. Hundreds of non-native species are found in damaged ecosystems (ignoring whether the species themselves are the cause, or the symptom, of damage).
    2. Permaculturists sometimes plant a few of these species in residential or small-farm landscapes.
    3. Therefore, permaculturists are damaging intact ecosystems, and this damage outweighs the benefits of their work.

    I don’t think #3 is defensible. I think this is a non-issue, a “what if” story. I think all we’re doing is arguing different philosophies of ecosystem restoration, one that argues that only natives can create a healthy ecosystem, and one arguing that hybrid native/exotic communities can also be healthy.

    And one correction: Gehron and Webster state that native assemblages have co-evolved for millions of years. This is not true. 15,000 years ago much of North America was under a mile of ice. Biota returned piecemeal (studies show that most species don’t move as communities, but as species), and species makeup has been shifting ever since. Most partnerships on this continent can be no more than a few thousand years old, and, as in the example of Douglas fir in NW prairies, may be much younger than that. Partnerships can happen very, very fast. Virtually all species were unbalanced, partnerless invaders at one time. We just don’t like what that looks like when we’re present for it.

    • says

      I strongly agree with Koreen Brennan’s statement: “Native plant lovers and permaculturists both care about the environment and want to preserve and enhance our natural resources. I will bet that if we focus on getting to root causes of these disturbances (…), we will find many ways to work together to address real causes”.

      I also think that we all agree that nature is infinitely complex (no need to talk about black-and-white again). It seems that we don’t agree on the facts or their interpretation. So let us keep looking at the facts.

      Dear Toby: Is this an actual quotation? If so, please supply a reference.

      ‘I think we have a false syllogism going on here:
      ” 1. Hundreds of non-native species are found in damaged ecosystems (ignoring whether the species themselves are the cause, or the symptom, of damage).
      2. Permaculturists sometimes plant a few of these species in residential or small-farm landscapes.
      3. Therefore, permaculturists are damaging intact ecosystems, and this damage outweighs the benefits of their work”.’

      It doesn’t sound like anything I have heard. I will let others rephrase those three points in a way more in agreement with the thinking of native plant advocates.

      As for your correction to Gehron and Webster statement “that native assemblages have co-evolved for millions of years. This is not true. . . Biota returned piecemeal (studies show that most species don’t move as communities, but as species).” Allow me a couple of corrections to your correction.

      It is true that communities probably don’t move in-toto; but certain assemblages and co-evolved assortments do and there is plenty of evidence for that. Host plants and their herbivores move together, so do specialized pollinators, many sorts of mycorrhizae and all kinds of symbionts. Co-evolved interactions take millions of years to form; for instance the exquisite interaction between a plant sending aromatic signals to parasitoid wasps when it finds itself under attack by the herbivore which that wasp feeds on. The chemical signals and behavioral responses do not develop overnight.

      And what about the weevils of the genus Blepharida and their host plants Bursera? ( The relationship started more than 100,000,000 years ago. It survived the breakup of Gondwana and the genetic diversification of both the plants and the beetles. With more than a hundred species each, distributed in the Americas and Africa, their relationship and their struggle go on. Chemistry and behavior and other mutual adjustments have continued through those eons.

      There are many other examples of fine tuned co-evolution that cannot be accomplished in a mere 15,000 years, much less a few hundreds. So Gehron and Webster statement remains valid.

      Answering a few other points made here and on the other page ( 1) We don’t know which species may become invasive or, just as bad, which ones carry pathogens or pests that may do so. Some take a long time and then explode; for instance, Kudzu is bad enough without its native pollinators; but recently the giant resin bee arrived from Asia and it is a good pollinator of Kudzu, so we can expect that species to become even more invasive than it already is ( 2) The plant itself may be well behaved but not the pathogens that it carries. 3) They don’t just attack plants in disturbed lands but also the ones in healthy ecosystems; think about the American chestnut, the American elm and a few others.

      We must remember that we were rather lucky with most of the early introductions of non-native crop plants. They had been cultivated for so long that they had become dependent on cultivation. But this is not the case with the most recent introductions. They have a much higher potential to become invasive. And we still don’t know enough. When we find out it is already too late.

      We should not use extinction of native species as the only yardstick. Functional extinctions as the ones of the American chestnut and the American elm, are bad enough. Or the significant drops in numbers of birds, for instance.

      For all these reasons it seems irresponsible to use non-native organisms, especially the more recent introductions.

      And, please don’t use the words “native-plant maniacs” even if you are referring to yourself in a former life :)
      Beatriz Moisset recently posted..The Yucca Moth and the Yucca

      • says

        Kevin–Great list of resources!

        Beatriz et al–

        My syllogism sums up what I have read here and elsewhere: how can permies justify planting exotics when they destroy intact ecosystems? I don’t think I’m putting words into people’s mouths with that. I’m trying to cut to the core of the logic, because I think the “therefore permies are doing harm” that Sue and others are concluding is not valid. I think we are simply arguing different strategies for restoration. And I think ours works better; it’s certainly a much larger toolkit of solutions, and I suspect with far fewer awful side effects, like the decades-long herbicide application of so many restoration projects.

        I can’t help myself here, so pardon the snark: When you stop eating and thus supporting massive monocultures of corn, wheat, soy, apples, rice, and every other non-native food plant that has done orders of magnitude more damage to ecosystems than any “invasive exotic,” I will stop thinking that autumn olive is useful.I’d like us to get the scale of harm in proportion here! The kettle is calling the pot black.

        But, you make very good points, and I can see I phrased some of my remarks very poorly. It’s true that, “The [Blepharida] relationship started more than 100,000,000 years ago.”

        So, in re-thinking: The right question is not, how old are these relationships, but: How long does it take them to form, or to re-form once one of the partners has moved? That’s the key to the invasive-species question. And you’ve answered that: it can happen very quickly. Kudzu’s old pollinating partner has followed it to the US after only a few decades. So I think we can expect its predators to arrive soon, or for some local omnivore or flexible-diet herbivore to find this great food source. I know that vivid imbalances likeKudzu monocultures (as opposed to the many that we are unaware of) are painful for us to see. But they are very common; we just ignore them when they involve natives (What did that dense stand of hemlock kill to get there?).

        I say this not to argue that it’s thus fine to introduce whatever we want. It’s not. But what do we do when these species are already here? That’s what interests me. I don’t think “spray, plant, and pray” is the answer, from either an effectiveness or ecological soundness point of view. And it doesn’t seem likely that, once the highway department has planted two million autumn olives and they have been naturalized over a wide area by millions of seed-spreading birds for 50 years, that a permaculturist in that area, planting two in a suburban backyard, amidst exotic bluegrass and apples from the Urals, is significantly going to exacerbate the problem. And we know that the benefits to wildlife and the soil in that yard are manifold. When huge areas nearby have been disturbed, then filled with millions of happy invaders that are finding unused resources, being spread by birds and mammals, pollinated by insects, and are otherwise already forming the partnerships that are allowing them to thrive, I can’t follow the logic that says that planting three in a yard is harmful or irresponsible, especially when a series of design criteria suggests it is going to be more beneficial in that yard than any other choice.

        About the idea that invasives are hitting intact communities or ecosystems: From what I can tell, the largest numbers of invasive species in North America are occurring east of the Mississippi. The West is generally too dry, except in riparian areas, for more than a few to take hold, but the regular rainfall in the East allows many to thrive. So why are they taking hold?

        I want to do some summing up, so pardon the repetition. The northern half of the East was under a mile of ice until about 12,000 years ago, so the assemblages there–and in the SE, since that area also warmed–have moved in since them. This process was very chaotic, as the climate warmed and tundra was replaced by aspens then spruces then more conifers then hardwoods and on and on (imagine all those invasions of intact ecosystems!). Climate fluctuated greatly during this period, so species were extending north and south and back again. Taken over a period of centuries or millennia, a vegetation map would show species washing back and forth like the tides. Not stable at all.

        About 9000 years ago, in the midst of this shifting vegetation, humans started burning the large Eastern (and Western) valleys and part of the uplands, altering the species mix to favor the vegetation they depended on. These intensive manipulations went on until 1500-1700 CE, when those tended ecosystems collapsed with the loss of their keystone species (Indians). Once again, a massive wave of assemblage reorganization went on at that time, with enormous species shifts. Nearby opportunist species moved into these changed conditions , often in huge monocultures, as pollen records show.

        After 1600 most of the Eastern lowlands and much else was cleared and farmed, and animal migratory patterns were greatly disturbed by hunting. Some hypothesize that the chestnut was made susceptible to the blight by the loss of huge phosphorus imports from passenger pigeons and other birds–again, the blight itself may have been a symptom, not cause.

        One sign of the magnitude of the disturbances are the stone walls all over New England. They were often built by Irish immigrants arriving around 1840. The soil in New England was not always stony; it eroded to near bedrock after 200 years of farming, hence the need to remove all those rocks. One of the photos I saw of invasive hardy kiwi showed it climbing over stone walls: the boundaries of former farms–not an intact ecosystem, but a rapidly shifting set of seral phases.

        The farms were largely abandoned in the early 1900s, precipitating another huge species rearrangement as early-succession forests moved in, often, again, in monocultures of sumac, swamp maple, hemlock, or black oaks. These forests are now 40-100 years old, still very young, and with many open niches. And from 1950 on they have been carved up by developers, with more enormous disturbances and open niches.

        Those open niches are a sign of incomplete “resource partitioning,” eco-speak for the way that species divide up available nutrients, light, and other resources. In undisturbed ecosystems, resource partitioning is very tight and finely divided, with virtually no unused resources except after disturbances that knock holes in this interlocked web. That’s why “intact” ecosystems are very hard to invade: there is little for new species to live on. And that’s why disturbed ecosystems, such as almost all of the Eastern US, are so easy to invade: resource partitioning has been disrupted by the constant disturbance over the last 400, or perhaps 12,000 years, making many opportunities for new species to move in.

        So when someone shows a picture of hardy kiwi climbing over several acres of young forest, it tells me that this is almost certainly a landscape with many broken resource links. And indeed, several of the photos I found when I googled “invasive kiwi” showed stone walls with kiwi crawling over them. Those were abandoned farms. A walk through even very old New England woods involves climbing over a lot of stone walls. It was pretty much all cleared and farmed. Not intact, but a mass of recent reconnections and attempts by species to develop new overall patterns of partitioning.

        It hurts us to see kiwi smothering trees. But that’s because we have such a tiny time frame. 100 years ago, that kiwi patch was a farm. 350 years ago it was a tangled mass of local, opportunistic species roaring into a collapsed ecosystem. And 500 years ago it was a food forest.

        A 100 or even 250 year old forest is not “intact.” It is in flux. In the Pacific NW, the “invader” there is often Douglas fir, a native that can choke out ancient native oaks, native madrones, ancient prairie, and old growth conifers after fire or disease. Species are always in flux. We can’t help but create an idea of how an area should look–not, please, covered in kiwi for 10 or 50 or 150 years!–but that’s our limited viewpoint, not nature’s. Now that so many links have been broken and pieces are missing, she, I think, is happy to find something to help catch sunlight and add biomass to this fluctuating young forest.

        The thing that intrigues me here is: The main “invaders” of forest are kudzu, Japanese bittersweet, hardy kiwi, and English ivy. So there is something in the broken resource partitioning of these sites that provides resources to shade-tolerant vines. Figure that one out, and you can stop the spread of these vines. The answer to most invasive problems is not to spray them, because nature has a much bigger budget, works longer hours, and is more patient than any restoration project. The answer is to change the conditions so they no longer favor the invader, or the invader will roll back in. (Really, we have the same goals!)

        We know that redirecting resources is the way to stop autumn olive, Scot’s broom, Himalayan blackberry, and other shade-intolerant disturbance-lovers. Stop disturbing, plant shade trees, build fertility (to inhibit N-fixing bacteria), and wait for your enemies to die. It may take 10-50 years, but I’ve seen it work in just a few years. Yanking and spraying is what they love. That’s why herbicide makers support restoration projects: they want the repeat business when the invaders inevitably return.

        So I think we need to focus our attention on real problems, not on unproven hypotheticals of permies planting Eleaegnus in back yards; to know when a species is a symptom or the problem itself; and to develop effective strategies–like stopping disturbance and creating shade, or learning whatever the hell is going on with shade-tolerant vines–when the effort to keep out an unwanted species is truly justified.

        • says

          I hear you Toby, but I would like to gently point out that we’re not talking about a single permaculturist planting one or two little eleagnus in her yard. The permaculture movement has hundreds of thousands of young, eager adherents, and it is earning, justifiably in many ways, a growing trust of the public. But when a friend of mine told me she planned to plant some hardy kiwi in her yard, and I pointed out that it had the potential to escape into her adjacent nearby young hardwood woodland (which was gradually moving toward becoming a more mature, more diverse hardwood forest, not covered in vines), and that it had the potential to become as disruptive and dominant as bittersweet, she was horrified. And mystified, that the permaculture article that had recommended hardy kiwi would do such a thing, without at least warning her.

          I’m pretty sure that no-one in this conversation, except the permaculturists, is talking about restoration efforts and their perhaps questionable goals and outcomes. What we’re talking about is preventing MORE situations that will require restoration.

          I do appreciate that we are in a critical time in the history of human existence on this earth. Ecosystems everywhere are about to undergo some shocking, and to us distressing, changes, as the planet warms. And I think it’s lovely that so many permaculturists are working to grow food and provide for themselves with while placing less demand on the earth’s resources.

          I personally don’t think that these efforts are going to make even a tiny bit of difference in the larger scope of the disaster that lies ahead (which can only be addressed by massive government effort… an effort will almost certainly never happen). But good for them for trying. I just wish they, and you, wouldn’t promote actions that you really can’t know will be harmless, or as you say, helpful. We don’t have that information yet. Not for sure, despite your detailed explanations.

          Others have derided Doug Tallamy’s book as “a theory looking for some data.” I would say that permaculture fits into that same category. Even permaculture founder David Holmgren says, in the review that you recommended, that he’s been waiting thirty years for evidence that would show that the “nativist ideology is a danger to the environment.” So now, permaculturists have a little bit of new data, which apparently calls into question a mountain of older data. So you say, let’s just agree that all that old data is wrong (and the reasons for this choice do look pretty self-serving, to an outsider). And I say: couldn’t we wait a bit? We don’t know yet that the new data is any truer than the old data. So in the meantime, howabout we try to be careful.

          Will it really be so hard on permaculturists to stop planting hardy kiwi and eleagnus? Surely there are other plants that can fulfill whatever (human-designated) functions those plants are chosen to fulfill. No. That’s not the issue here. I realize that. It’s a whole system of belief that’s at stake.

          • says

            And, Sue, I hear you, when it comes to practice: anyone who plants a shade-tolerate vine in a climate with warm-season rainfall is, if nothing else, being incredibly rude, politically naive, and asking for trouble, even if no harmful ecological consequences come of it. It’s a stupid thing to do for many reasons. The shade-tolerant vines are potentially the most damaging exotics to forests of almost any age. Get your kiwis at the store. Plant a grape. To be honest, since I live on the West Coast, I didn’t know that hardy kiwi was classed as invasive in the East, and I’m hoping that the person who wrote that article didn’t either.

            I don’t feel the same way about the disturbance- and light-requiring shrubs like autumn olives, because they can’t move into forest easily and the prairies they move into really need fire to be called prairies, which will easily control any shrub, buckthorn included. They are in badly disturbed landscapes, and those will be “invaded” until we stop disturbing them and let resource partitioning mature, which won’t happen in anyone’s current lifetime. But again, it is foolish to plant a species that is considered invasive in your area, because, even if there is no ecological harm, you will then be dragged into endless arguments like this one ;-) and give permaculture a bad name. There are, as you say, almost always other species to use; I use bladder senna and goumi instead of the bird-spread Elaeagnus species. We permies need to be smarter about this stuff, but we have the “everyone else is an idiot” gene passed down from BIll Mollison to contend with, which attracted a lot of cantankerous, anti-social types in the early years of permaculture. Like I say, a good designer uses a native first, a tested exotic next, and should never need an unknown or a locally known invasive. That last is hard, because what’s harmless and even incredibly useful in one place–say, the West, can be wildly spreading elsewhere. I’m not waving the white flag here–I think claims about invasive species (as opposed to disturbance) being the cause of damage are at least 80% xenophobic, ecologically ignorant nonsense, and have the science to back that up. But I would strongly discourage anyone from planting a shade-tolerant problem vine in a moist climate.

        • says

          Dear Toby:

          You are putting words into people’s mouths. Your syllogism is false, because you made it false. Please, inform yourself a little better.

          You are also putting words into people’s mouths when you say: “spray, plant, and pray”. Is this how you describe the work of restoration ecologists? You dismiss all their studies and hard work, while at the same time you don’t have a yardstick to measure whether in fact your system of restoration works better. Do a little googling to check the facts. Better yet, use Google scholar to get the more rigorous studies. There are so many publications under “restoration ecology” (707,000), that I decided to narrow it down to only the most recent ones, 2012, (,39); feel free to check others. I found 7,820 results, covering a wide range of studies from prairies to wetlands, urban areas, pit mines, logged forests; from molecular studies to soil biota, to socio-economic issues. Plenty of facts in many of those studies. Google scholar lists 286 publications under “permaculture” in the same period of time ( None of these studies provides facts, as far as I can see; I gave up after the 50th or so. You think your strategy works better, please give us the facts.

          You suggested googling “invasion biology controversy” and I did so, except that I used Google scholar once again to get a better level of information. I had to resort to “-cancer” to eliminate the irrelevant studies on invasive cancer cells. There are about 7,440 results for “invasion biology” in 2012 alone ( Invasion biology is alive and well to the present. So much for being 15 years behind the times. Out of these results, 525 include the word “controversy” ( Please, notice that the controversy in most of them is about details or facets of invasion biology, not about the discipline itself. The media loves controversy so it made a big deal of the Davis paper in Nature (2011) and the response by other scientists. That is why you find many hits around it when you use the ordinary Google but not when you look at the work of invasion biology researchers.

          Growing your own food, having a nature area within a bee-fly distance of your back door, cutting down on pesticide-ridden monoculture-driven agriculture… all that is beautiful. I would love to see that. I want that concept to succeed. But we need facts. Please give us the facts, learn the facts. Don’t say: I didn’t know that kiwi was invasive in Massachusetts. The facts were at the tips of your fingers. Don’t act first and find the facts later. It may be too late.

          Just one more thing: the giant resin bee did not follow the Kudzu. It was introduced accidentally by humans. An example of invasional meltdown?
          Beatriz Moisset recently posted..Pollinator Conservation Short Course

  13. Kevin Bayuk says

    For those interested in additional references, I offer up the following links:

    Courting Controversy with a New View on Exotic Species
    Another article sharing insights from biologists and a book that invites nuanced perspectives on “exotics” and “natives” and evolution and eco-synthesis.

    Alien Species Reconsidered: Finding a Value in Non-Natives
    This article introduces some recent “mainstream” writing about the evidence for “ecosynthesis” – essentially that, when we observe the role of “invasive” species we may find that they are part of the evolution of the ecosystem. More reason not to judge vegetation or fauna on its “immigration status?”

    Video of David Theodropoulos Presentation (*start at 6min)
    A long video of David Theodropoulos sharing insights from his book. See additional links here for presentation and written summary.

    The Pesticides and Politics of America’s Eco-War
    Unfortunate anecdote about the tragic use of herbicides and chemicals in the attempt to “restore ecosystems.” This article showcases some of the complexity of oversimplifying vegetation into “natives” and “exotics.”

    David Theodropoulos has been at the forefront of the “natives vs. exotics” discussion long before most of us were even aware that this issue was more nuanced than mainstream media would have us think. Read his writings and decide for yourself.

    INVASION of the ALIENS! Science or Pseudoscience?
    David Theodropoulos has recreated a slideshow lecture that he gives in HTML format, loaded with case examples. Be sure to click the slide links while you read the page.

    Professor Arthur Shapiro’s comment on the Environmental Impact Report for the Natural Areas Program
    MillionTrees has reproduced Arthur Shapiro’s letter the the San Francisco Natural Areas program regarding their programs and policies. Arthur is the leading lepidopterist at UC Davis and has the “bona fides” to speak about this subject (his own words).

    Ecologists: Time to End Invasive-Species Persecution | Wired Science |
    18 ecologists sign on to a pear reviewed essay in the June 9, 2011 issue of Nature entitled, “Don’t judge species on their origins.”

    Native Plants: Restoring to an Idea
    Toby Hemmenway explores land use ethics with native and invasive plants.

    • says

      Thanks, Kevin, for gathering all these links in one place. I will definitely check them out.

      I’ve always been fascinated by how the pendulum swings in social and scientific movements, and we appear to be in the midst of that phenomenon here. However, I do stand by my concern, as I explain in greater detail in my post at, that although the scienctific consensus may appear to be shifting with regard to non-native opportunistic plants, there is as yet no widespread agreement about the subject, and until that happens, I believe it makes good sense to operate with care and caution, especially for those whose belief system rests entirely on the notion that agriculture has always caused tremendous harm, and we permaculturists are here now to save the world.

  14. says

    One more connection: Here’s how my snarky “then stop eating corn!” remark links to the planting of autumn olive. (Which I don’t use. I prefer its cousin, goumi instead, since along with supporting birds, holding soil, using little water, and fixing nitrogen, it has edible berries.) My goal is to turn my yard, and other land that is more or less permanently out of the wild matrix, like suburbia and near-city small farms, into a multifunctional habitat that supports other species while it lets humans support ourselves too. A number of species that are considered invasive provide excellent ways to get me there, doing all the things that I just listed above and plenty more. My goal is to make my own yard as productive as possible, but not by importing fertilizer and other resources, but by creating naturally renewing fertility, habitat for pest-fighting bugs and birds, and, in the outer parts of a good sized yard, natives. I think an excellent way to balance our needs with the rest of nature’s is the permaculture zone system, of useful, multifunctional plants near the house (most of which support native partners), and have more natives the farther out you go. This shows me my footprint honestly, where I can see it.

    My autumn olive helps save wild land. By using my yard to provide resources that would otherwise be grown in rural areas, I am no longer commissioning as much farming on land that really could be wild. An urban yard will never be an intact ecosystem; use it to grow food with native-supporting guild plantings. A yard can link to wild species and still provide food for humans, but if the owner of a natives-only yard is buying granola and bread, they are undoing whatever good they think they are doing by pushing the consequences of their consumption out of sight. I think it’s honest and responsible to take care of our own needs as close to us as we can, so that some farm can shrink its footprint, let rural land become an ecosystem and not a monoculture, and not have my name on the land they are plowing. I’m not there yet, but I’m working on it.

  15. says

    I am going to celebrate my Interdependence Day with some bits of my own perspective in honor of the fact that we are all interdependent upon each other, all life on this planet depends on one another for survival ultimately.

    To avoid echoing a lot of what has already been said so well by others, I will add in that in permaculture design, we have a specific set of land use ethic that helps us decide when, where and how humans should interact with ecological systems.

    The first ethic is that when we have an intact ecosystem, we protect it. There’s not many of these left, we have decimated most ecosystems anywhere near human settlements. If there are people within a days driving distance you can probably assess that is impacted, decimated (species count) and the soil is denuded from its original pre-settler condition. By protect we do not mean to fence it off and allow no use, this would be a denial of the fact that the First Peoples actively interacted and tended the ecosystems they lived among.

    The second ethic is that when we have a ecosystem that is degraded and dysfunctional , we want to bring it back to functioning condition as efficiently as possible in terms of time and energy. When we see these so called “invasions” of exotics, this is a good indicator that the ecosystem is not functioning as a whole. Intact ecosystems are notoriously difficult to invade because the resources are in tight cycle amongst the many and diverse players in the system.

    What we are probably seeing when we see an opportunistic plant move in is a temporal imbalance. Eventually as that plant is doing its job the conditions it requires to thrive will change, the factors leading to it’s success will fade and new plants will have their time to come in to the system, leading to more complexity and continually adding to the system in a positive feedback loop. If we continually eradicate the the very solution, in other words pick at the scab, the wound will take longer and longer to heal. This does not mean we advocate for a hand-off approach and simply watch the imbalance unfold on it’s own, we can often speed things along by adding in more diversity and helping these plants do their job quicker, see below.

    When we teach this subject, we like to introduce the idea of changing the word “invasion” to “imbalance”. Invader brings along such strong feelings and we humans all too easily seem to tend towards xenophobia. When we see an imbalance, we can almost exclusively trace it back to some human disturbance. If left to her own devices, nature will fix these imbalances and she will use the best tools she has at her disposal without sentimentality or any sort of anachronistic notion of what “should” be there. However, it may take a long long time, longer than any of us or our children will be around to see, for it takes a forest 500 – 1000 years or more to create one inch of topsoil whereas the disturbance of humans can erode FEET in a matter of years and we can do this over many millions of acres.

    When we see the disturbance, we like to advocate for these three questions:

    1. Why is it there?
    2. What is it doing?
    3. How can we help?

    By asking these question and harmonizing with our pioneer plant allies, we can speed along ecosystem synthesis many fold. The strategies to do this are some of the core concepts of permaculture and are certainly why we get the reputation of using “invasives”. We see what they are up to and choose to compose with their function rather than impose that we know better.

    The third and final land use ethic is that we meet human needs on as small a piece of land as possible using complex and divers assemblages of plants and animals. They key here for me is “on as small a piece of land as possible”. Permaculture is absolutely anthropocentric, in a way. We recognize that if we can as a people learn to meet our needs sensibly in harmony with all other life, we can create the conditions conducive for more life instead of taking them away. Every little bit of productivity we can get out of our dense human settlements means that much less farming OUT THERE.

    I hate to bring up the hypocrisy of it all, but for those who plant natives exclusively around their homes and in the urban/sub-urban setting I have a question, what did you eat today and where did it come from? I want to ask this question with care and understanding, because I know that most everyone doing such things is coming from a place of deep compassion and love for our planet and her children. I would propose you ask yourself another question, what about the natives out there where most of our food is being produced?

    It turns out that we can be 10 to 100 times more productive close in to humans interaction than any industrial farm can be in terms of food produced, the only thing industrial farms are efficient at is liquidating natural resources for financial profit. The sad truth is that our current model of large scale agriculture has destroyed more ecosystems and contributed more to climate change than all other factors combined.

    What we are proposing is that we do our best to meet as many of our needs, if not all of then, right within our settlements. I would posit that you could save far more native plants and animals and protect far more ecosystems in general by growing as much food as close to home as possible and reducing your need for imported food.

    I dont want to paint a false dichotomy either, it’s not all food nor is it all natives, we strive for both. The truth is, there is no reason for these these to be mutually exclusive of each other, we can have productive foodscapes that ALSO provide habitat for native pollinators. These productive areas within human settled areas probably will include some plants on the top 10 most wanted list of invasives, but they will always be close at hand and managed by us humans.

    When it comes down to it, most of us really love plants, all of them. Personally I have no room in my heart to hate any of them and it hurts me a bit when I hear words like “invaders”. Would it be suitable to use that kind of word if we were to talk about people that come from another place to do the hard work that so few from here are willing to do? I prefer to think of these plant as “hard working pioneers” doing the sometimes thankless work of getting these ecosystems back into shape. I for one, want to help out as much as I am given the chance to do so. By jumping in, rolling up our sleeves and helping them get it done, we help create the condition conducive for more life to thrive. In the end I think most of us can agree that is a great outcome to work toward.

    Thanks for reading my ramble, Happy Interdependence Day!

    • says

      I said it before and I’ll say it again: FACTS! FACTS! FACTS!
      Your point about invaders being indicators of degraded environments requires supporting data, as well as a few of your other comments. About hating invasives; this has nothing to do with it. Please read: “I do not Hate Invasive Species”
      Growing your own food and reducing the amount of land devoted to mega-agriculture is commendable. The issue here is that introduced species can cause serious damage to the environment. About forty percent of endangered species in the world are endangered because of non-natives. So, the continued use of introduced species is a monumental mistake. We don’t know which ones will become invasive and what their impact will be; so it is essential that we stop this practice. It is Russian roulette.
      Beatriz Moisset recently posted..Of Spring Beauties and Lesser Celandines

      • says

        Hi Beatrix, thanks for providing us the opportunity to dig deeper into the discussion. I hope we can come up with some new valuable perspectives together.

        About facts, I can quote entire excerpts from Theodropolous’ book ere but I request that you go ahead and pick it up and read for yourself, years ago he took it upon himself to dig up and present the facts and I am running off the evidence he has provided in those pages, they far outweigh any other evidence I have seen to the contrary. Barring reading his book, “Invasion Biology: Critique of a Psuedo-Science”, I recommended watching the following 15 minute video:

        Seems to me that the field of Invasion Biology has a lot of work to do if it ever hopes to present enough evidence to support it’s own argument in light of the facts and evidence provided by Mr. Theodropolous.

        That statement of fact you level here, “The issue here is that introduced species can cause serious damage to the environment. About forty percent of endangered species in the world are endangered because of non-natives.” is in fact, not a fact. I challenge anyone to show me a so called invasive plant pushing out native plants that does not have linked to it a previously anthropogenic disturbance to the ecosystem. You wont find one easily, i assure you.

        When we see a disturbance (please, lets not use the term invasion, it has war-like connotations and threaded within it’s meaning are hateful feelings) it nearly always is not seen in a functioning ecosystem. These disturbance are happening in natural systems on the path to regeneration after massive species decimation and resource depletion. These disturbed systems are pale shadows of the ecosystem previous diversity, it is not helpful to think of them as whole. Many of these have barely 1/100th of the species diversity they once exhibited; that’s not just decimation, let’s call it centimation.

        I read the article you linked there and I see your distinction about the word hate and it was clear to me even before hand. Yes of course you love all plants, as long as they don’t move around and “invade”. You hate their invasive characteristics when they are put in a place they “don’t belong”. Let us remember that our language is a model of the world to be, what we say out into the world becomes part of the common thought pattern, and we are responsible for our words and the feelings they cause as well as they actions they bring after their meaning is taken. I cant imagine it would be OK to talk about humans, their immigration status, and their different cultures as they live here among us in the same way. It is a slippery slope of mental trickery, if it’s OK to talk about plants in such ways then who is the next target?

        You also in the article make a statement that human dispersal is unnatural, you do realize many of the native plants and animals on the North American continent came over the land bridge with humans, right? Not to mention birds and other animals carrying seed in their feathers/fur/feces for literally eons, I ask the question, why isn’t the whole planet a big mess of invasives, surely they have had long enough to push out all the natives?

        You may go on to argue that it is the rate of dispersal which is not natural. I would of course rebut that with widespread species extinction of the very critters who used to do the job of dispersal compounded with the alarming rate of destruction caused by ourselves, it is the increased rate of dispersal by humans that we need more than ever! What we are proposing is intelligent dispersal along with increased dispersal.

        I could go on and on of course, I do so love this topic. I am doing my best to ask some critical question that I hope frame the discussion. As an exercise, I challenge anyone reading this to go out and look at an example of imbalance and ask these questions:

        1. What is it doing there?
        -where is the human disturbance?

        2. What is it doing?
        -what ecosystemic regeneration functions is the pioneer performing?

        3. How can I help?
        -is this the best plant for the job? Can I add any more to speed it along? Is there a management practice to speed things along that doesnt include destruction and setting it back?

        • says

          Between your comments and those of Toby, there is enough material for a couple of blog posts, so I will deal with them later. Suffice it to say that what I mean for facts is data, data collected to prove or disprove a point, properly planned, collected, analyzed and interpreted. For instance your point “What we are probably seeing when we see an opportunistic plant move in is a temporal imbalance” or when Toby says that his restorations using non-natives work better than other methods need to be substantiated by hard data. I cannot find any. Please, show it to me.
          This is not to say that I don’t admire some of the things that you are doing with urban gardening. I am in favor of that kind of things.
          Beatriz Moisset recently posted..Pollinator Conservation Short Course

          • says

            We’re both fans of good data (15 years as a geneticist sets the mold), and permaculture is sadly lacking in direct data to support it. We’re not funded, only now getting permaculture into universities where research is done (give us 5 years!) and often much more interested in helping soil grow microbes and attracting bugs than in counting them. Our bad. So we have to turn to fields like agroforestry, organic farming, mycology, and even invasion biology to indirectly use data to support our practices, and the data are there. Since I’m on a ranch in a remote part of Montana for the summer (helping restore native prairie by first planting exotic cover crop mixes, since the local native plant people and ecologists say it works fastest, speaking of anecdotes) and my internet connection here is s-l-o-w, doing Google Scholar searches would eat up so much of my day that it’s just not worth it for this discussion. Lame, I know, but I have better things to do. I know of studies showing exotic casuarina has been used for rapid forest establishment after hurricanes in the Bahamas, and a number of others. Those are back home in my library. Sigh. Beatriz, always eager to score points, will have a field day with that.

            I’ve done my own study, on 10 acres of land I owned in southern Oregon. And I know that data and anecdote are not the same. But I did get numbers. I compared my land to 70 acres of commercial forest next to it, all clearcut simultaneously in the 1970s. The commercial land was sprayed repeatedly and replanted with Douglas fir and Ponderosa pine immediately. My 10 acres was purchased from the timber company before that could be done, and sat, eroding for a decade. Scot’s broom, Himalayan blackberry, and Pacific Madrone moved in. The former two covered roughly 60 percent of my land when I bought it in 1993. The land had been replanted, finally, with 900 douglas fir seedlings in 1984. At first I started ripping out the exotics, but found they grew back even faster after disturbance. So I gave up. Then I noticed that the firs seemed bigger in the berry patches than in the clearings, and the timber company land was losing a large portion of its trees. Overall, sampling about 100 trees in random transects on both parcels in 2002, I found that the firs in blackberries and broom were about 30% larger in diameter at breast height (dbh) than the commercial firs where blackberry/broom was not present, even though my firs were 10 years younger. Tree loss was far less on my land, but since I didn’t know how many trees had been planted on the timberland, I couldn’t measure it. But my trees were much denser, and I know that timber companies usually plant at higher densities than my land had been.

            In 2004, when we left, the timber company clearcut their land again, calling their planting a failure, leaving most of their spindly, thin trees on the ground. My trees were healthy, dense, and the blackberry and Scot’s broom cover had receded to about 15% of cover, with no interference on my part. The remaining exotics were in poor health.They are hard to find on that land now.

            Again, I know that this is more anecdote than data, but this, and many similar observations made by foresters in the area showed me that some exotics make excellent nurse crops that then recede as the ecosystem matures. And I’ve seen similar results at dozens of permaculture sites: land that is lush and vibrant, with high insect and bird counts (real counts!) compared to the deserts in the surrounding yards. It’s one reason I’d prefer that people here go after your neighbor and his lawn instead of my permie buddies.

            And It’s part of why I am pretty sanguine when I hear of disturbance-loving exotics moving in. We are in the midst of the brief moment, unlikely to ever happen again in human history, where thousands of species are moving faster than partnerships can form. And nobody, including me, likes it. But they will, as the resin-bee story and many others show, form or re-form their partnerships with other species in a decade, or a century or five – maddeningly slow to us, but nothing on an ecological, let alone evolutionary time scale. Since there is not one case of species loss due to exotics (as opposed to development and agriculture), and we see plenty of data that fractured ecological partnerships can re-knit, I am just going to grit my teeth and try to learn what is going on in this amazing laboratory we have created, and take comfort in the certainty that healthy communities are forming in this, and will continue to form. Invasive species are a symptom that follows the destruction of healthy ecosystems, and I’m much more interested in fighting the cause – overconsumption – than the symptom. Permaculture is one way to do that.

        • says

          What is unnatural about human introductions is the sheer numbers. The planet has never seen anything like it, not even when India collided with the rest of Asia or when the Panama bridge was formed between North and South America. With the magnitude of travel and trade taking place, we have created a colossal meltdown of natural barriers.

          I guess that, to you, it would be natural to carry some live plants from NY to CA, plant them there and unleash Japanese beetles on the West Coast. In the way back you could bring some eggs or cocoons of light brown apple moth hiding on some plants. Of course you wouldn’t do that! Not intentionally, at least. But do you realize that there are over 2,000 species of non-native insects in North America? Most of them introduced via live plants. How can you predict what will happen next with constant human-assisted introductions?
          Beatriz Moisset recently posted..Of Spring Beauties and Lesser Celandines

  16. Kate Gehron says

    Sincere thanks to Toby Hemenway for his thoughtful responses and his statement that “when it comes to practice: anyone who plants a shade-tolerate vine in a climate with warm-season rainfall is, if nothing else, being incredibly rude, politically naive, and asking for trouble, even if no harmful ecological consequences come of it. It’s a stupid thing to do for many reasons. The shade-tolerant vines are potentially the most damaging exotics to forests of almost any age. Get your kiwis at the store. Plant a grape.” This reflects the moderate and practical attitude of caution that we have been discussing.

    I hope that Hemenway will use his position as a leader in permaculture to recommend this attitude of moderation to others such as David Cody, who defends, above, the dubious conclusions that those of us concerned here about invasives find most alarming: “By . . . harmonizing with our pioneer plant allies, we can speed along ecosystem synthesis many fold. The strategies to do this are some of the core concepts of permaculture and are certainly why we get the reputation of using ‘invasives.’ We see what they are up to and choose to compose with their function rather than impose that we know better.” It is stunningly presumptuous to say that permaculturists have sufficient understanding of natural systems to “speed them along.” Obviously, not all practitioners would agree with Cody’s statement, but it is extremely problematic.

    This leads me to consider a subject that has not yet been raised but seems like it’s worthy of discussion, and that is the teleological understanding of nature that has been expressed by Hemenway and at least one other commenter. There are numerous examples above of Hemenway ascribing intention to nature: “nature throwing a green band-aid over disturbance”; “kiwi is . . . trying to create biomass and photosynthesis”; “nature using what’s available to solve a problem”; “Russian olive is trying to turn your lawn back into the forest . . . that it wants to be”; “Nature never says, ‘a functioning ecosystem can only contain these species.’ She works by function, not by species”; “Why, then, does nature favor the exotics now? Could they be better at doing the jobs nature needs?”; “Nature is using whatever is available to restore plant cover, take out disadvantaged species that can’t deal with the new conditions, and bring in missing functions like biomass accumulation, soil building and retention, air purification, and all the rest.” Nature isn’t “trying” to do anything in particular, doesn’t have a job. Nature is a human abstraction. “Damage” and “healing” and other terms related to health and sickness can be understood only as expressions of human priorities. In fact, needs ascribed to nature are often actually human needs, as evidenced by the “missing functions” listed in the final quote above. This is an enumeration of ecosystem services–things that are required for people to thrive.

    Perhaps Hemenway speaks of nature’s intentions only figuratively. Regardless, it seems that he is promoting a narrative that may allow followers to feel comfortable “helping” nature evolve faster by introducing new species. It would be just as easy to conclude that the presence of invasives in a disturbed area indicates that a compromised system is becoming sicker from a secondary infection; a symptom of damage can of course cause more damage. I don’t endorse either simplistic picture; I just bring this up to point out that we shouldn’t ascribe a value-laden story line to natural phenomena. This very same complaint has been lodged against so-called nativists, and it is a sound critique.

    It may be that some permaculturists value human interests over biodiversity conservation. (Hemenway’s assertion that nature “works by function, not by species,” seems to suggest that his main concern is the creation of functional relationships that sustain ecosystem services for people, not the prevention of extinction; local extinctions are a real risk where specialist species no longer have access to the plants they use to survive. Other permaculturist commenters have expressed leanings similar to Hemenway’s.) Perhaps it is the case that our goals are actually a bit different.

    However, if permaculturists do feel local biodiversity conservation is a major priority, it seems that they need to offer up a convincing body of quantitative evidence that past examples of “invasions” have not, as has been concluded in many studies, often simplified existing functional relationships and jeopardized the continued local survival of native species. In general, attributing purpose to nature, and asserting that we can know what that purpose is, appears to be a way for people to justify their actions in the absence of such quantitative evidence.

    • says

      Kate: Outstanding post! And I apologize for spitting out all these posts, but the writers here are so intelligent, and the subject so dear and fascinating, and I’ve been camping for a week, that I can’t stop.

      My narrative style, rather than analytical language, is intentional. I’ve made a study of teleology (from Aristotle to Mayr to Deacon and back again) and conclude that since the human mind is essentially a meaning-maker, the fight to eliminate intention from language is a losing battle – it will simply reappear at a deeper or more subtle level. So I want my teleology to be explicit so we can see it. Years ago there was a huge to-do in the journal Science asking if science could be value free, and the conclusion eventually was that it can’t be. Yes, I could replace “trying to throw a green bandaid” with “mature ecosystems tend to have higher levels of standing biomass than immature or disturbed sites, (see Bigbore, 1967) and recruit from the available species pool (Yawning, 1971) with no statistically significant difference in origin of recruited species (Dullard, 1991) but with success of invasion dependent on the rate of biomass accumulation of each species (Lifesuckedout, 2004) and . . .” but you can see why I don’t. Plus, then we have to define mature and biomass and . . . we go down the spiral. And is there anyone here who didn’t already know about species recruitment not being dependent on species origin? Both statements arrive at the same place, and one is a whole lot more interesting to read, if requiring a sympathetic reader – and you unsympathetic readers know who you are. I could convert every teleological statement to the ugly monster I wrote above, but this is not a science journal. But your point is well made, so I ask you and every other reader to rewrite my words for yourself if that makes you feel more comfortable with language. All communication requires, first, a reader willing to try to understand, rather than defeat, the writer. Only one or two here don’t know that.

      Trends exist in the progression from young to more mature ecosystems, and these include increasing biomass, richer trophic patterning, larger organisms, greater biodiversity, more and narrower niches, etc, etc. Given an absence of disturbance, these trends usually prevail. And this is what I mean by what nature is “trying” to do.

      I disagree that using terms like ecosystem services and function are anthropocentric. All organisms need ecosystem services and functional ecosystems. They die without them, just as people do. I don’t see anything in my language that suggests I value humans more. I see several people here make the same unwarranted assumption, that permaculturists give priority to humans, and it isn’t true – the human realm is a subset of the more-than-human realm and is impoverished when the world around us is impoverished. ONE MORE TIME: I don’t know of a single permaculturist who values “human interests over biodiversity conservation.” We all came to it from a love of the natural world and a horror of what humans are doing to it. But we think we can have both people (fewer of them!) and biodiversity instead of humans as cancer, unlike what industrial culture will allow, and are trying to follow up every promising lead as to how to do that.

      Hybrid communities seem a very promising avenue, as is now becoming apparent to restoration biologists (see Theodoropoulos, which is not with me here, for some data). We are surrounded by these hybrids, they are vigorous – like most hybrids – and we will never eliminate them except in rare cases. So permaculturists, like many restorationists, are trying to understand them, mimic them, and see if we can use them for restoration, food, habitat, etc. Since they are so good at generating biomass, creating humus, and increasing detritivore numbers – things lacking in the agriculture that has replaced about 30% of the earth’s ecosystems – we have high hopes for their role in replacing, or undoing some of the damage done by, conventional landscaping as well as industrial farming.

  17. Jim Kleinwachter says

    I work for a not for profit land trust in northern Ill. Besides the usual villians – Buckthorn, Honeysuckle and the dreaded multi-flora rose — the newest threats are from Japanese Barberry, Burning Bush and Vinca! I can show you pictures of woodlands infested with these ornamental favorites.
    If hardy Kiwi is beginning to be a problem in the East — How long before we have this problem in the Midwest ?
    Oh yes I like to eat – but there are costs to everything!!!

  18. Dee says

    Fantastic article. It seems to me it’s common sense that introducing a plant from another county, for example, Japan to this eco system is going to be disasterous to the native plants & wildlife. The natural forces that kept it in check in it’s native eco system aren’t present in it’s new environment, where it can grow unchecked & choke out all of the native wildlife here. After subscribing to wren song, I was educated about the importance of planting native plants, & I began to do just that. It wasn’t something I thought about before, but now it’s so natural & the right thing to do for the environment. I added more native plants, & from there I have graduated to planting Milkweed, & other host & nectar plants for native butterflies. I have planted a native butterfly garden that I’m very proud of. I recently had 4 Painted Ladies born & released in the garden. Why does this man fight he right thing to do? Is he worried if he can’t plant these invasive plants he won’t make his money? Truely evil things like that are usually motivated by money. Or maybe he has no common sense…

  19. Hilary Persky says

    Beatriz, your posts are an education. Thank you for your to the point and scientific approach.

    I am extremely uneasy with lecture style used elsewhere in relation to nature with a capital N…let alone as a woman.

    Further, the people I have encountered working to manage local areas characterize invasives as a sympton; I have detected no “hegemonical” xenophobia.

    As someone new to this issue, it may be of interest to somone out there that I find–from the reading I am doing here–that the ideologiocal tone resides largely on the side suggesting the other is being sentimental and ideological.

    This is a familiar situation (in my experience) and I wonder if it’s rather gendered.

    That aside, thank you for the education, all. Really, really valuable.

  20. Dee says

    In [Sue Reed’s] vision of a ‘native’ world, would she like to see all but the first (indigenous) peoples removed from the ecosystem in which they have artificially been introduced – including us Europeans in North America?”

    This is a ridiculous assumption & has NOTHING to do with the topic at hand. A cheap shot, hitting below the belt. A completely inappropriate comment. He doesn’t have a valid argument, so like the saying goes, when you don’t have a defense, go on the offense.
    Mr. Falk is supposed to be an educated man, yet he is so ignorant to the obvious, that non native species are causing great harm to the environment. There are scientific facts to prove this. Is he also in denial of climate change? That is also upon us, & backed up with scientific facts, however, ignorant people like him spread the message that global warming & climate change are a myth.
    As responsible gardeners, we educate ourselves, & become stewards of of the earth. We plant native, to support the wildlife in our area, whether local or migrating through. It’s a positive step that helps are wildlife neighbors survive. When we plant responsibly & plant native, we undo a some of the damage that has been inflicted on nature by humans.
    I hope Mr. Falks message doesn’t reach any more people with his irresponsible, untrue & dangerous message. I have concerns that people will believe him, especially beginner gardeners who are learning about how we can affect nature in a positive way. His message gives people the green light to continue to plant as many invasive species as they like, believing they are doing no harm. It’s a proven scientific fact that invasives cause harm to the environment.
    We are all connected. When we damage the wildlife & poisen the earth, we are poisening ourselves. The wildlife supports us, pollinates our food supply, & gives us life. It sustains the human race. We can’t survive without it. We need to respect & support our wildlife, & stop destroying it.
    Why would Mr. Falk spread this message? Why would he encourage others to be irresponsible & cause more damage to the environment? How can he be so blind to the obvious damage invasives have caused? I’m very concerned a supposedly college educated man is writing & lecturing this garbage, & influencing others with his false statements. He does a lot of damage to the environmental movement & sets it back years. Mr. Falk is on a mission to destroy wildlife, to destroy native plant populations, & cause more damage to the environment. He needs to learn how to be a resposible steward of the environment.
    Why is Mr. Falk spreading this damaging message? Is he getting paid, or monetary contributions from any companies that are damaging the environment, that will benefit from this message?

  21. Lynne Sullivan says

    The problem here is not permaculture, but an individual. I have never before encountered a permaculture writer or lecturer who advocates the use of non-native species in areas where they can become invasive.

    Let’s not throw the baby out with the bathwater… permaculture is predicated on self-supporting guilds of plants. It makes no sense that this philosophy would condone the use of invasive species which threaten any natural guilds or native species.

  22. Jack Moran says

    Holy Timoly,

    I just discovered this board after checking out Ben Falks work based on a YouTube of a NOFA VT presentation. I was impressed with Ben, especially with his use of footage from Hurricane Irene and how clear and obvious he makes that case that traditional clear tillage and monoculture destroys good water retention and fertility systems.

    When he recommended Autumn Olive, Black Locust and Hardy Kiwi that I was not familiar with, I wanted to learn more but I was sad to realize that they were not legal in Massachusetts. I just finished writing an e-mail to Ben asking if he happened to have any substitutes.

    After doing so, I just got curious if others had run into a similar issue and stumbled on this site. Wow, I had no idea such a controversy existed around this.

    It’s actually a little disappointing. I think so much of what we need right now is for there to be good strong cooperation. My newbie perspective has me concluding this:

    Ben Faulk’s work and the permaculture movement have merit.
    Invasive Species are an issue.

    I think we should have enough respect for each other to take the time to work together to find the meritorious common ground and move forward with that.



    • Lynne says

      As a Master Gardener, I focus on advising “local gardeners”. But in an age of globalization, the term “local” may encompass a great area. It is important that gardeners recognize what is a good plant in one area may become a nightmare in others. We cannot afford to jeopardize any more diversity by introducing plants that will overwhelm the natural flora.

      There are many examples of huge mistakes: kudzu in the southern states is a case in point. Japanese knotweed is another, and I have battled this behemoth in Ontario. If you don’t know the potential dangers of any plant that is not native to YOUR AREA, don’t use it. Ask a local Master Gardener, a local conservation office or a government agency. Do not take the word of garden centres (which sell innocent plants that become invasive, such as periwinkle, purple loosestrife and English ivies.)

      • Jack Moran says


        I’m not sure if your reply was in response to my post.

        I think the heart of the matter with respect to this is that we are all in the same boat. I don’t think any of us has all of the answers. As imperfect as Ben’s use of Hardy Kiwi in VT may have been, he is none the less a person working to make the world better. Maybe he should utilize native species instead of non-natives. He is a gardener and someone working to make the world better. There is certainly a whole world of merit in his water management systems and his other systems for heating and fertility management that are based on non-polluting, highly durable naturally occurring cycles, regardless of plant selection.

        There is a world of merit in battling behemoth invasive issues as well and you deserve gratitude for fighting that fight, so thank you!, thank you!, thank you!

        On the other hand writing off an entire slice of the population of folks that misguided or not may have ever used such a plant, I don’t really believe that we are served well by this. Warts or no, these folks are really working to make the world a better place and helping others to do so.

        If the true objective here is to educate and uplift folks to a more enlightened understanding of our superior perspective, then I think it would be more well served by befriending such folks and offering a model of your own example as a superior alternative, rather than writing off the people that may have committed the mistake. As the old saying goes, you get further with honey than you do with vinegar. And the world just might be a little sweeter for it.

        I hope this message finds you well and that you have a great holiday season!


        Jack Moran

        • Lynne says

          Jack, I don’t write anyone off. I do try to make them aware that any given plant may be “native” in one location, and “invasive” in another. We have to consider and preserve what natural ecosystems remain. This is not to say we should only plant natives. We’d all be pretty hungry if that were the case. But we do need to be cautious about introducing non-natives to an area. This includes genetically modified foods, which are not native to anywhere, and pose a very real threat to the native, hybrid, and introduced species that our livelihood depends on.


    • says

      Thank you, Jack, for your thoughtful comment. I would be very interested to know how Mr. Falk responded to your question about using alternatives to invasive species. It has been my experience that many permaculture practitioners (Mr. Falk included) deny the existence, and even the very concept, of invasive species. They typically call them “novel” or some other benign word, and then go on to inform us, often quite aggressively (and in the case of Mr. Falk, insultingly) that we who care about protecting natural systems do not have a long-term view of nature, that all introduced species have a place in nature and that it is not our place to judge them negatively. They do not seem to understand the concepts of ecosystem structure and evolutionary biodiversity, preferring instead to put forth the notion that since natural forces (which includes humans) have always moved species around, there is really nothing wrong with continuing to do more of that, without any concern for the consequences.

      The original point I made, which apparently set Mr. Falk’s hair on fire, was that permaculturists who promote the idea of planting whatever plants will serve human desires (often called “needs”) are no different from agriculturists throughout history. They place the wishes of humans above the needs, the actual life needs, of other creatures and the rest of nature. Their entire philosophy is based on the notion that we should use the land to produce whatever we need. Period. The rest of their arguments are constructed, sometimes quite cleverly, to support this fundamental precept. The fact that they have erected a quite lovely but essentially self-referential, self-reinforcing and self-serving school of thought, and have collected thousands of gullible followers, does not make their philosophy correct.

      I do agree that agriculture as currently practiced causes much harm in the world. I do agree that we all should grow more of our own food. I do agree that there is much that is wrong in the world, and idealistic dreamers can help make things better. I do not, however, agree that we humans should have the appalling hubris to continue moving species around the globe without any concern about how our actions will affect other creatures.

      • Jack Moran says

        Sue and Lynne,

        I share concern about genetically engineered species and some of the hybridization processes that have become common. I know that here in Massachusetts invasive species choke out a number of significant river systems, and as a fisherman, I find that particularly disappointing. Volunteers spend days each spring pulling them (loostrife I believe) from the water.

        Sue, you refer to a correct philosophy. Is there a philosophy that you subscribe to?

        When I think about what I like about the concept of permaculture, is a long time frame, 100 years or more. For example, I am currently looking at American Chestnut and Black Walnut as some of the items that I would like to cultivate and thinking about my grandchildren enjoying the shade or some of the nuts from the trees. Before reading about it, I think I like most folks thought about gardening/farming as an annual clear cut – till the ground bare process. I can’t help but think that this is a good thing to keep the longer timeline in focus.

        Is this not what you’re getting from what you hear?



        P.S. There’s an organization called the American Chestnut Foundation that is breeding an American Chestnut to have resistance to the blight that was responsible for most of the loss of the species. Is there anything wrong with their approach to reproducing Chestnut Trees?

        • says

          Hi again Jack. As you wisely observe, this is all very complex. The only philosophy I myself subscribe to is my own belief that in everything we do, we all need to give a higher priority to the needs of non-human creatures, and get out of the way, as best we can, of nature’s processes. This doesn’t mean we have to have no needs or place no demands on the natural world, as that of course would be impossible. I just think that we could do a better job of trying to understand what’s going on in nature, and we should evolve our cultural belief system to give greater value to the respect and care for other creatures’ needs.

          For example, even in this blog which focuses specifically on native plants, many writers continue to make recommendations that emphasize adjusting how plants LOOK, rather than how they function within their larger ecosystem. “Neaten up the edges.” “Prune out the excess.” “Clear away, tidy up, take down.” These are the words and ideas of people who see gardening primarily as a form of decorating, with the ultimate purpose being to satisfy their own human desire for some ideal of prettiness.

          I believe that ecological gardening, or conservation gardening, or whatever you want to call it, really should move beyond that old-fashioned way of thinking, and put nature first. What creatures are living in that “untidy edge?” What other species might thrive in “that mess?” How can I make every landscape more robust, healthy and full of biodiversity? These are the things that I care about.

          Re permaculture’s “long time frame:” this idea is not new to permaculture. Conservationists have been doing it for decades. In addition, I wonder: how can permaculturists profess a commitment to the long time frame when they turn a completely blind eye to the effects of planting invasive species in their gardens, species which then sometimes almost immediately colonize nearby natural areas and destroy the biodiversity therein (witness the hardy kiwi invasion in woodlands just beside a hardy kiwi plantation)? What kind of long time frame is operating when a permaculture enthusiast, who promised to prevent her autumn olive grove (hey, they’re great nitrogen fixers!) from becoming invasive by clipping off all the seeds, decides to move, or grows old, or misses one season due to illness or bad weather? That sort of assurance is ridiculous and impossible. It is a false dream promoted by permaculturists who just want to do what they want to do, and have invented a variety of justifications that have nothing to do with taking care of the earth.

          Re the American Chestnut efforts… I don’t feel that I know enough to comment specifically. I myself am not a huge fan of tinkering with species, and these days I’m actually much more concerned about the effects of climate change on our forests (and the need to find ways to store MUCH more carbon in forest trees and soil) than I am with re-introducing a tree that has succumbed as a result of the mistakes of short-sighted humans. However, I do realize that chestnut tress were a huge component of huge tracts of valuable forest ecosystems, and the folks working to breed blight-resistance into a new species have reason to believe they are doing good.

  23. Lynne says

    Where is the PERMA in permaculture? In nature, sustainability and survival relies on two essential strategies: diversity and adaptation. This latter involves the evolution of species to accommodate unique and adverse conditions in order to thrive whereas it would otherwise perish. Diversity is not opposite, but complimentary. A wide variety of species sustains the ecosystem, as nutrients, water, and temperature fluctuate. The plants that have adapted best to the current conditions will increase in numbers. When the conditions change, other species will dominate.

    My initial impression of permaculture was that it strives to work with nature. Now I find proponents that thumb their nose at nature’s methods of ensuring balance and survival. There are many open-pollinated food crops, many native plants that provide food for humans and animals, many cultivated varieties that can be grown responsibly (avoiding monocropping, etc.) There is very little to be gained by introducing invasive species that jeopardize this diversity.

    Take a lesson from the insect world: when non-native species find a ripe new territory, there is no natural enemy to control them. So we have Emerald Ash Borers and Asian Longhorned Beetles. Likewise, rampant invasive plants can erase diversity, preventing further natural adaptations. We need all the egg baskets we can carry.


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