Permaculture’s Internal Contradiction

A couple of years ago I gave a presentation to a hall full of Master Gardeners on my favorite topic: saving energy in our landscapes. I pointed out that if we gardened with more native plants, this would support regional pollinators, thereby potentially reducing the energy costs associated with replacing a vital ecological service. Compared to some of the talk’s other suggestions, this was a relatively minor point, but I felt it was vital to include…to my regret, as it turned out.

Nobody disagrees that we should grow more food locally.

Here’s why. The first question at the end of my talk was a belligerent shout from the back of the hall: “If we garden with native plants, how would you suggest we get enough Vitamin C in our diets, assuming we choose not to import oranges from thousands of miles away? What’s your answer to that?”

Um. First of all, I never said anything about growing only native plants, nor anything about food. And second, why are you so angry? I don’t exactly remember how I responded, but this guy’s quarrelsome attitude cast a pall over all further discussion.

This was my first encounter with the rude tone that many permaculturists feel entitled to use when speaking to others whom they seem to perceive as either misguided, idiotic or some sort of threat. It was not to be my last.

A few months ago, I publicly questioned the widespread permaculture practice of growing non-native perennial plants that are known to be disruptive to nearby natural ecosystems. Here’s what I wrote:

“Like all the worst systems of agriculture and horticulture in our past, this new approach still places human wishes and desires (often called “needs”) in the center of the equation.”

Vitriolic response to this statement came very quickly from an offended permaculture advocate. I’m quite sure he didn’t mean to accidentally prove my point when he started his broadside with this:

“Actually, permaculture does the opposite of most agriculture systems as it facilitates the development of diverse, highly complex, and resilient ecosystems in which human needs (italics mine) such as food, water, and shelter are provided for locally.”

Hmm…isn’t that what I said? As far as agriculture goes, the “local” part may be unique to this new kind of farming, but the self-granted permission to meet human needs without being hampered by concern about unlikely negative consequences (and they’re always presented as unlikely), well, that sounds sadly familiar. Think Monsanto, Dow Chemical, GM crops, etc.

I would like to be clear here, right at the start, that I believe there is a lot in permaculture’s system of beliefs that makes good sense. I have no gripe with the movement’s worthy ideals and hard-working advocates; in fact, I admire them. I also recognize that many permaculturists do take great care to avoid invasive plants. It is the arguments of those fiercely defensive spokespeople, many who claim to speak for the movement as a whole, that concern me here.

European buckthorn, favored by permacuture as a nitrogen-fixer, invading nearby woods. Note its lush, late-autumn foliage amid the bare trees.

My point is this: Considering that the first stated ethic of permaculture is “Care for the Earth,” how can practitioners ignore the notion of non-native plants causing harm, and promote the growing of several non-native plants species already known to be invasive?

Since writing my original statement, I’ve learned that this is not a new issue in the permaculture world. I don’t know when it first arose, but clearly there’s a problem here that has not yet been resolved.

So let’s take a closer look at some of the claims made in defense of this practice that seems to contradict one of the movement’s founding edicts. I do not include here every argument that permaculturists make, and I will not air the most absurd and insulting ones; my goal is to highlight a few main issues.

Claim: Invasive species don’t harm natural ecosystems.

This blanket denial says that harm from invasive species is not real because the term “invasive species” is overly-emotional and impossible to define, and besides, there’s no such thing as natural ecosystems left to be harmed because humans have always altered nature. Permaculturist Eric Toensmeier writes in “The New American Landscape” that we should call the impact of invasive species not “harm,” but rather “change.” The evidence most often given for this outlook comes from the book “Invasion Biology,” by biologist Mark Davis.


Mr. Davis writes: “It is time the field [of conservation biology] puts to rest once and for all any and all general claims that introduced invasive species represent the second greatest global extinction threat to imperiled native species, and instead focuses on the many other sorts of effects that non-native species are having, including impacts on biodiversity that do not involve actual extinctions (italics mine, P. 274).

Hey. How about that. According to this oft-quoted expert, not only do invasive species exist, they also affect biodiversity. So, those who justify permaculture’s use of invasive plants by quoting this book are selectively believing only the data that serves their own interest. (Or maybe they just forgot to read the second half of that sentence?) This does not make their claims true.

As another commenter has pointed out, Mark Davis also states: “We are not suggesting that conservationists abandon their efforts to mitigate serious problems caused by some introduced species.” Hm…I haven’t yet read all of “Invasion Biology,” but I wonder what else in this book negates permaculturists’ assertions.

Also, to clarify: extinction is not the problem that native plant proponents are trying to prevent. The goal of native plant advocacy is to protect diverse ecosystems and sustain healthy natural food webs.

Claim: New scientific conclusions support permaculture.

Conservation biology and the study of invasive species is a science in flux. An avid permaculturist recently wrote in a tirade against what he called the “bunk” of native plant proponents, saying: “Look out. Science works over long time periods to dissolve poor ideas and scientific/cultural misconceptions.”


Yes, it is well-known that scientific understanding evolves. We are learning that some of the most disruptive plants currently turning once-diverse ecosystems into monocultures were introduced 50 or even 100 years before they started to spread explosively. How can permaculturists be sure that the new data they use to justify their actions this year will still be true next year, or in 50 years? Given that the science of invasion biology is clearly in flux, wouldn’t it make sense to be more careful in how we treat our precious planet, rather than less?

Oriental bittersweet: ever upward.

Claim: We’re already living with invasive plants just fine.

I recently talked with a permaculture advocate whom I like and respect. To my question about the widespread use of hardy kiwi as a food crop, he calmly explained that, from a permaculture perspective, this vine is sort of the equivalent of Oriental bittersweet, and if it escaped it would occupy the same general niche. So, he said, since we’re already living with bittersweet, this would be no worse.


Well, as much as I respect him, this logic eludes me. Do permaculturists believe that because humans have already made a mess of things, and the planet’s not dead yet, we should all feel free to keep on making the same kinds of mistakes? Wouldn’t it make more sense, when seeing the shocking explosion of invasive species everywhere, to think: wow, even though it’s clear we can’t get rid of all these problems, we should really try not to cause any more problems? Isn’t it true that the whole notion of permaculture came into being based on observations that conventional agriculture has always ruined land wherever it has gone? This practice seems no different.


In conclusion


Source of Leopold’s “Land Ethic” and much more.

Ecologist Aldo Leopold wrote in 1948:

“One of humanity’s greatest challenges is to live on land without spoiling it.”

Permaculturists claim that their “whole systems” approach to growing food is necessary to save the world from the post-peak oil crisis ahead. This self-granted imperative, however, does not entitle them to accidentally trash the world. Later saying “Oops, we got that part wrong…sorry…” is not acceptable. So, I would like to pose two questions to permaculture proponents everywhere:

First: Even if the chances seem (to you) slim that potentially disruptive species will escape your gardens and cause harm, even if you want us to believe that nature will be just fine! don’t worry so much!… wouldn’t it make sense to have as your starting point an attitude of caution?

And second: Since you base your belief system on observations about the countless unwitting and short-sighted errors made by agriculturists everywhere throughout history, why won’t you consider the long-term consequences of your own actions and advice, and take into account the actual whole system of nature, not just the (supposedly) closed systems that you design and manage and promote as the solution to the world’s problems?

Permaculture is a marvelously complex set of beliefs, with much to offer. However, its practice of ignoring the potential impact of non-native species on surrounding natural areas seems to be in direct violation of the movement’s simultaneously most basic and most lofty goal – to care for the planet.

Does such an internal contradiction undermine the movement’s effectiveness? Does it keep permaculture from being taken seriously? To me, the answer is clearly yes. Perhaps others see it differently. But it is a paradox that deserves careful, honest evaluation, not dismissive insults and self-serving distortions of reality.


© 2012, 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. says

    Sue, I agree that there are some permaculture practices, which do not seem to serve the overall principles. Use of invasive plants is high on that list.

    Here in Florida there are some widely-planted crops that have become invasive. Taro (Colocasia esculenta) and malanga (Xanthosoma sagittifolium) are both members of the arum family (Araceae) and have been on the list of most invasive plants.

    When writing our new book, “Organic Methods for Growing Vegetables in Florida,” my co-author and I put them in the “Not Recommended” list and urged people to remove them from their properties. We also recommended several native crops and native pollinator plants in and around the edible gardens. The book will be published in Feb. 2013.
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    • Susan Egerton says

      Hi Ginny, I have a big problem with what I think is the Xanthosoma sagittifolium plant which was bought a few years back as an ornamental. It has now spread into my pond, across the dam and into the wet lands on my neighbors property. I have tried to spray it with organic killer but nothing has worked. Is there a way to kill it?

    • Ladakh says


      Xanthosoma sagittifolium has edible tubers. Maybe you should stop spraying it and start eating it? You have a perennial food source that you would rather kill than eat? That’s kind of strange.

  2. Ursula Vernon says

    It was precisely that attitude that turned me off to permaculture. I want to like it, I think there’s a lot to it, but you mention “y’know, there’s a lot of invasive plants on this list” and people go crazy defensive. Not just like ornamental gardeners going “But I LIKE Brazilian verbena!” but REALLY crazy. I once said something about autumn olive being a horrible scourge where I was, and quite literally got a “Well, I planted it, and I don’t regret it! You can’t tell me what to do! This is America!”


    Permaculture, unfortunately, while it holds some truly wonderful people I’ve been privileged to know, also seems to encompass that odd intersection where gardeners meet survivalists convinced that the government wants their guns and they have to provide their own food for when the system collapses. So you do get some people who’s worldview is a bit…peculiar. And as it’s a big tent movement, the loud weirdos who see any attempt to say “Maybe we shouldn’t do that,” as an infringement on their personal sovereignty have a very loud voice.

    • says

      I guess we also have to admit that the native plant movement also contains some people with extreme views (like me?). I don’t mind that permaculturists and native plant proponents are trying to solve different problems. Nor that they want us all to change our diets and eat all perennial food crops (good luck with that). I just mind that in their refusal to even face up to and directly address the issue of invasive plants, their actions are making the world worse.

      • says

        I don’t find the use of non-native plants nearly so obnoxious as I do watching native plant zealots wandering around the woods spraying glyphosate. Talk about making the world worse.

        • says

          Have you actually seen “native plant zealots” using glyphosate the way you describe? I know that some nature centers and restoration sites resort to chemical controls as a last resource. They all prefer the use of mechanical and biological controls whenever possible. Integrated Pest Management (IPM) plays an important role on restoration of natural landscapes.
          The sites Native Plants and Wildlife Gardens, Beautiful Wildlife Garden and Ecosystem Gardening, provide abundant examples of ways to avoid the use of pesticides. You may want to read some of the articles.
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          • Mike says

            Yes, unfortunately I have personally seen “cultural restoration” enthusiasts use round-up and other chemicals to impose their human preferences upon nature, and I have seen countless examples of others advocating for this sort of use.

            This is how I understand their arguments: since the native soil ecology and plant communities necessary to support native ecosystems has been irreparably changed, application of extensive energy and chemical resources are necessary to fight nature in order to re-impose human desires about “culture,” “purity,” and “aesthetics” upon landscapes.

            I personally know some awesome native gardeners who simultaneously promote the benefits (low-maintenance, low input) of native plants while complaining of how much time, energy, and money maintaining their “native” garden requires!

            Meanwhile, my “Permaculture garden”–certainly the scourge of many cultural restoration enthusiasts– hosts a greater number of native plants, provides exceptional habitat for native insects and animals, creates a far greater bio-diversity, lowers my ecological impact by providing food, fuel and craft materials, and requires almost no energy, little labor, no weeding, and certainly NEVER any chemicals!

            Every Permaculturalist I know of LOVES native species! I LOVE native species!

            But so long as you conflate human ideas about the cultural make-up and “purity” of “native” communities with the “earth,” or “nature,” I will not find your argument compelling.

            What I think is needed is a thoughtful contribution to where and when native species should be used, how they can be preserved, and how you define the goals of “cultural restoration” in the context of “earth care.” Certainly, poisoning or violently removing non-human species based upon some human notion of where they’re “allowed” to go, is anathema to me. The use of precious non-renewable resources towards this end should be a non-starter.

    • Bandito Mosquito says

      Methinks you just want to have an issue where there really isn’t any issue. I’ve not heard one spokesperson in the Permaculture movement ever say that the use of invasive species is a common practice. Actually, the use of native, local plants should be the first choice, then non-native species. Yes, native species use is not as prolific as it should be, but the use of TRUE invasive species in Permaculture isn’t either. My suggestion to you is to dig a little deeper into the world of Permaculture and learn that there are farmers out there that are currently farming on a large scale supporting both themselves and local communities with native species and no use or mention of any use invasive species. Keep calm, carry on.

  3. QuietProtest says

    This article is ironic to me in that I have had similar experiences with Native Plant advocates (who, I must say, worship at the altar of Doug Tallamy.) In asking/inquirying about just what a Native Plant is (I have read and heard it is anything that dates back to a pre-European population) as well as the role humans have in the evolution of landscapes (humans do qualify as being part of the landscape and part of its evolution, yes?), I have encountered quite of bit of arrogance on all sides leading to quiet negotiated responses, a try to “talk them down” in order to get the information and not the philosophy. That there is divisiveness with Permacultural practices and Native Plant boosters does not surprise me at all: everyone needs to take a breath. Radical practice of a belief system should not necessarily negate another belief system. Everyone seems defensive and I, for one, will continue to do my research, plant a “mixed” plot (horrors!) and be happy in my yard with the many critters who reside there.

    • says

      Hello QuietProtest, and thanks for writing. I agree with you that one person’s beliefs should not negate another’s beliefs. I also think no-one is saying that native plant proponents are trying to negate permaculturists’ beliefs.

      What I am trying to do is get from some permaculturist somewhere an answer to a simple question: how can you keep promoting the use of invasive plants that everyone can plainly see have already destroyed once-intact ecosystems? (This question leaves aside the whole issue of the plants that we don’t yet know are invasive.) So far, nobody, including you, has actually addressed this simple question. What I get, when permaculturists respond, is insults and sarcasm and condescension and changing the subject. I would like even one permaculturist to just answer the question that I ask.

      • says

        Hi Sue,

        I can understand that you may not be getting satisfactory answers from those in the permaculture community (and I count myself among them), however if “even one permaculturist” answering that question would suffice, note that you already quote that answer in another of your related posts:

        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). [ ]

        Jacke (and coauthor Eric Toensmeier) wrote that prior to you asking the question, but it still looks to me like the kind of answer you’d appreciate.

        For what it’s worth, the instructors of my permaculture certification course expressed what I believe to be the “mainstream” position of permaculture, which is that one should always choose a native species to fill a desired role in a design, unless no native is available that can fill that role, or unless there exists a non-native that both A) fills the role in a strongly superior manner and B) can reasonably be expected to be well behaved in the broader ecosystem.

        Okay, so that’s certainly not agreeing with your position that non-natives represent a greater risk than the average permaculturist seems to recognize. But it is a stance that is less, shall we say, staunch than the reactions you seem to sometimes encounter.

        Also, if you don’t mind a little chiding, you write as though you were surprised by vitriolic response to your originally posted question: “Like all the worst systems of agriculture and horticulture in our past, this new approach still places human wishes and desires (often called ‘needs’) in the center of the equation.” I don’t find it especially surprising that some would react strongly to having their method of work described as one of “the worst systems of agriculture and horticulture.” Them’s fighting words! :)

        In my own permaculture practice, I always cross-check my plant recommendations against the lists of invasive plants in the states where I am creating my designs, in my case Vermont and New Hampshire. I check not only the legally binding “prohibited plants” lists but the watch-lists of potentially problematic plants as well. (Similarly, even though Vermont does not have restrictions on Ribes species while New Hampshire does, I steer my Vermont clients toward those Ribes cultivars that are approved by New Hampshire out of deference to the NH authorities’ concerns.) Neither Vermont nor New Hampshire list hardy kiwi, and I had not actually heard of it being problematic before reading your posts.

        Again, this isn’t a direct response to your question, and so long as I’m not recommending specifically identified invasives/probable-invasive I continue to include non-natives in (some of) my designs.

        Anyhow, that’s what I’ve got to say for now. . . lots of lawn to mow at my inlaws today. -Jonathan

        • says

          Hi Jonathan, and thank you so much for your contribution to this discussion. I’m learning, in this process, that a big piece of permaculture’s philosophy rests on the idea that what we have called “invasive” (a term that I would very much like to change to “disruptive”) plants are not actually causing harm, as we have previously defined it. Instead, they are helping nature. That seems to be the gist of it. I still stand by my original statement that this system is driven by the imperative to meet human needs first – use plants that “fill a role,” a role that we define as necessary for our own plans – and consider nature second.

          A new commenter recently posted links to several studies (at, so I’ve got more reading to do!

          • says

            Hi Sue,

            It sounds like you are thinking in particular of responses like that of Toby Hemenway below. To be clear, I haven’t talked about the “invasives” issue very much with other permaculture practitioners/advocates, so this is largely a gut response on my part: that said, I think you correctly identify a strain of thought in the permaculture community, especially with regard to nitrogen fixing or dynamic accumulator plants. (In case you aren’t familiar with the term, “dynamic accumulator” describes plants that accumulate soil minerals more readily than the average, especially from deeper levels of soil, and subsequently release those minerals into the upper levels via leaf fall and decay–making the minerals more accessible to other plants.) As Hemenway argues, massive swaths of the land area in question have undergone massive ecological disruptions over the past couple of centuries. In Vermont, for example, the virtual clear-cutting of the entire state, including on all but the steepest mountain slopes, has meant the loss of vast quantities of topsoil. If a nitrogen-fixing plant such as black locust (whose known “native” range is not all that far from Vermont) establishes widely, how are we to judge between the possibilities that A) it is behaving in an ecologically disruptive way, and B) it is fulfilling an ecological restoration need by replenishing degraded soils with what would be normal levels of nitrogen absent colonial and post-colonial disruptions? For whatever reasons, permaculturists apparently tend to be satisfied with answer B, while those approaching the question from the world of native-plant preservation tend toward answer A.

            As for the degree to which the permaculture approach prioritizes human needs, from my reading and the presentation of my certification instructors, I interpret it this way: it is impossible to understand or address ecological function and health separately from human social function and health. Given the size and spread of human population, the impact of human technologies, and the imperatives of (existing) political-economic arrangements, no meaningful area of Earth’s living systems is independent of human effects. This means that, to address ecological distress we must necessarily simultaneously address human needs (whether biologically or socially determined), and vice versa, as they are unavoidably linked. For example, harkening back to the original trigger for this series of blog posts and comments, humans have a biological need for vitamin C, and social and technological arrangements in North America mean that, for the most part, North Americans will get it one way or another. It might come from locally grown produce, or from distantly grown produce, or synthesized in factories in China that are so polluting even the Chinese government, when under international spotlight, requires restrictions on the factories’ function (if Wikipedia is to be trusted: In the case of produce, the produce must be of a sort that is acceptable to the socially determined culinary “needs” of the particular culture in question. (It might also come from raw whale meat, but we can probably agree to safely ignore that option.) Each of these options clearly has existing or potential ecological negatives involved. (And for what it is worth, permaculturists on average are just as eager to push for revision of socially determined “needs” as they are to take chances with the use of non-native plant species; permaculturists overlap heavily with wild food foragers, and often promote little-known edible native species and make other efforts to nudge culinary tastes toward ecologically friendliness. Similarly, permaculturists, by and large, push for changes to our political-economic system in the hopes of a human society whose determination of and fulfillment of human needs will better accord with the needs of non-human ecology.)

            So apparently at the talk you gave, there was someone present who has determined that the first source of vitamin C is, all things considered, the net positive solution for the whole system of humans+nonhuman ecology. Why that person would lash out at you (if indeed you correctly interpreted their tone of voice) for saying things that could be interpreted as implying that the calculation leads to a different net result has more to do with his/her being a jerk than with permaculture as an approach to design. But, as you hint, permaculture is also something of a “movement” in addition to being a design methodology, for better or for worse, and movements can develop internal cultural momentum toward an us-vs.-them perception. I don’t see the permaculture scene as having reached a tipping point toward us-vs.-them’ism, but no doubt some fraction of those in the scene are more susceptible to that tendency than others, and, as a general rule in life, those will often be the most vocal in the group.


        • Ruth Parnall says

          If Jonathan is typical of landscape designers who are well trained in permaculture principles and techniques, I’d say “Let’s have more of them!” He sounds like a sensitive and sensible and probably effective practitioner.

  4. Ed Colahan says

    The previous commenter has a valid point: There is also much controversy within the native plant advocacy community about what constitutes “native” and what’s most appropriate for a given situation. There are self-described “purists” among us who contend we should use only open-pollinated specimens known to have existed in this or that county prior to European settlement (although the last time I checked, plants can’t actually read the map); there are others whose definition is basically anything-native-to-North-America-is-close-enough; and the rest of us fall somewhere in between. I agree that each of us needs to do the best he or she can with the information available to us while remaining open to the variety of views expressed on sites like this one.

    For me, as a garden designer, I deal with clients who often don’t give a fig about a plant’s ancestry or its affect (good or bad) on the local ecosystem as long as it looks good in their back yard. I stand my ground when it comes to known invasives, but if I can use a smaller cultivar of a native plant to satisfy them rather than an exotic alternative, that seems to me to be a good compromise. On the other hand, I firmly believe that a purple coneflower should actually be purple, and not look like a carnation.

    And getting back to Sue’s point… I think the most important take-away is that we should be able to calmly and rationally discuss our differences of opinion. It’s a good thing to have strongly held beliefs, but we should also be willing to analyze and question those beliefs. Like it or not, none of us has all the right answers.

    • says

      Thanks for your comments, Ed. I agree that this issues are complex and multi-dimensional. And of course nobody has all the right answers. But when I look at and hear about the explosive spread of hardy kiwi in parts of New England and the Midwest, I am completely mystified that people who claim to care for the Earth, people who proudly state that their aim is to promote biodiveristy, would then continue to recommend and use hardy kiwi as a staple of their perennial food-crop plans. This does not seem to be a complex issue.

        • GregMartin says

          Would love to find out!

          How invasive is hardy kiwi? How do we measure this? There’s been a male and female pair fruiting away in NH not too far from my home in a mixed field/forest area. The female has been fruiting away for at least 15 years and when I walk the area I’ve not seen any seedlings. Seems like a perfect area for it to spread into…lots of wildlife and forest edge. The fruit that isn’t picked seems to just fall off and rot on the ground. I know there’s one large male seedling that is growing in the wild in western MA. How many other sites are documented? How many sites are required before the plant is concidered an invasive threat?

  5. says

    This is exactly the same problem I have with permaculture and why I’m experimenting with my own ‘Native Food Forest’. We live on a former cornfield and to me it is not a matter of ‘survival’ but of restoring the soil and creating natural habitats that provide food for wildlife and humans too. I believe that the solution to sustainable agriculture lies in integrating permaculture methods with local native plant lists. So many wonderful native plants add nitrogen to the soil and and there are many native edible perennials yet waiting to be discovered. I love the idea of perennial vegetables – seems like so much less work than the annuals… This spring we tasted redbud flowers for the first time – delicious! It’s been fun researching local ecosystem compositions, plant characteristics and plant uses – although there doesn’t seem to be much written about how native plants affect the soil. Does anyone know of books about the subject?

  6. says

    What you have stated is true. The problem I see as with many other issues in gardening is that some believe their views are written in granite and can not be questioned. Not even the perception of that taking place.

    My gardening practice is focused in as little as possible effort, wasting energy in weeding, irrigating and such. No palm trees, hedges, lawns, pesticides, herbicides, fertilizer, except home made, compost/compost tea. Native and endemic plants collected or swapped, nothing from nurseries. Therefore, my plant collection is not only based on aesthetics but most important the urban/concrete/asphalt/saline breeze/heat context of Santurce, Puerto Rico where I live and the local flora/fauna.

    Excellent post.
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    • says

      Your landscape/garden must be fascinating! Now I’ve gotta go look up where Santurce is in Puerto Rico. And I agree with you: low-energy input is a great way to garden!

  7. says

    Good subject.
    It seems like there’s a lot of survivalists and stealth gardeners, and plenty of the RWNJs who claim permaculture as their own.

    I initially believed that permaculture was about self-sustainability, but a tiny bit of exposure to something that seems like a great idea on the surface, leaves a bad taste in one’s mouth.

    I’m not sure what could possibly be bringing out this amount of hostility and defensiveness in the “true believers”, but they seem to be doing more harm than good to their cause.

    The clannish hostility reminds me of the scary story of Cryonics at Alcor.

    I wonder how long it’s gonna take before we start hearing Ruby Ridge and Waco type stories in connection with permaculture…
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    • says

      For sure, everyone has a right to be passionate about their beliefs…. the problem here is that some of permaculturists’ actions have potential to lead to a really regrettable outcome (acres and acres of depauperated ecosystems,) and I just want all the proponents of this belief system to think carefully about what they’re doing. The intensity of their reactions is, perhaps, no worse than the intensity of other strong believers, including some native plant proponents, but I’m trying to overlook that aspect of the discussion and focus on substance.

  8. says

    [quote]The intensity of their reactions is, perhaps, no worse than the intensity of other strong believers, including some native plant proponents…[/quote]


    I’m not sure that it’s going to be possible to have rational discourse with people unable or unwilling to admit to the possibility that their system has room for improvement, but good luck with the attempt.
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  9. says

    Sue, let me reply to your remark,
    “how can you keep promoting the use of invasive plants that everyone can plainly see have already destroyed once-intact ecosystems? ”

    What “intact ecosystems” do you mean? Can you give examples of pristine ones that have been “destroyed?” Because invasion biologists are learning that that is a myth, unsupported by science. Here’s’ one problem. The major river valleys, and much else, of North America were burned regularly by native people for thousands of years, and selected for trees like chestnut, white oak, walnut, beechnut, hickory, and an understory of cherry and crabapple. Most of the low-elevation land in this continent was highly manipulated. When Europeans arrived and exterminated the native people, these highly tended ecosystems collapsed, and for about 300 years degraded into tangled thickets (“the dark forest primeval” of Emerson et al), until a very different assemblage of plants predominated (swamp oaks, conifers, etc). Then many of the European plants that were brought over moved into these degraded food forests and established themselves. Meanwhile, the east and midwest were cleared and planted to farms. Then in the early 1900 the Eastern farms were largely abandoned and many other species moved into this highly disturbed landscape. Most of the forests in New England have been disturbed for 500 years or so, and most of them are very new. So where is this “intact landscape? All that bittersweet and kiwi is moving into a highly degraded, disturbed landscape. The photo you show above is not of an old growth forest; it looks from the little I can tell like farmland that was abandoned about 40-80 years ago. Of course buckthorn and many other species are moving into it. Showing a picture of buckthorn building the soil and otherwise filling the holes of abandoned, burned out farmland that’s full of young trees says to me you don’t understand the ecology of the place. There are many, many open niches in land like that, and we have so badly impoverished the landscape that nature no longer has the full palette of species to work with to fill all the functions she needs. Plus there are many new and unused resource flows there (fertilizer runoff, old manure, voids where the species killed by farmers are missing). Nature will fill these with whatever is handy, uncaring if they are from Europe or an ancient forest. That’s why species turn “invasive,” even after 50 years or more of seeming innocuous: because we open up niches for them, like abandoning most of the Eastern farms.

    I’m not saying we should throw up our hands and say, “well, that’s how it is.” And I’m not among the extremists on both sides who insult the others. I’m trying to answer the question, “How can we understand what is really happening and use our understanding to minimize human impact and preserve biodiversity?” And the data really seem to be saying two things: that our disturbance is most of the problem, and that nature is using all the resources she can to undo it in a complex process that we don’t grasp at all. Our first reaction to bittersweet or loosestrife is “how horrible!” But on further looking, we see that loosestrife is good at cleaning up pollution–that’s why it predominates, because the natives can’t survive in the new conditions. And it supports the full array of local insects. Just killing it sets nature back in her healing process. These hybrid communities are nature doing the best she can, and I doubt if our little primate brains can encompass the magic she’s accomplishing. Just pulling bittersweet off the new edge cut by a developer in the forest, sentencing sun-intolerant trees to a slow death, is hopeless. The bittersweet appears to be there to accelerate the death of these doomed trees, so they can be replaced with sun-tolerant species. It’s much more complex that “bittersweet is evil.” It’s doing the work nature needs, with the best she has available in a poor setting.

    I was on the board of Seattle’s Native Plant Society, so my native plant cred (and love) is pretty good. I’m sorry there are foul-mouthed extremists on both sides–you should hear what I’ve been called by natives-only enthusiasts! But we really are trying to accomplish the same thing, and need to be aware, on both sides, of all the bias and baggage we bring to this, and try to set it aside. Invasion biology is being re-shaped, and the arguments against invasive exotics are dwindling. Let’s not let pictures of kiwi and buckthorn fool us into thinking the surface ugliness isn’t part of a larger process.
    Toby Hemenway recently posted..Fear and the Three-Day Food Supply

    • says

      “the arguments against invasive exotics are dwindling”. On the contrary, the numbers of publications on the subject have been growing steadily as shown by a Google scholar search. Please check the two following criteria: ‘”invasive species” economic impact’ (31,600 entries) and ‘”invasive species” wildlife impact’ (30,600 entries); more than half of all those publications took place in the last 5 years.

      There has been a 5 fold increase in publications in the past 10 years for both of those searches, from 1,240 entries in 2002 to 5,290 in 2011 for ‘”invasive species” economic impact’ and from 1,270 entries in 2002 to 4,980 in 2011 for ‘”invasive species” wildlife impact’.

      Perhaps this is not a valid argument because this trend of increased publications applies everywhere else. So, for the sake of comparison I looked at “pollinator economic impact”. We all know that concern for pollinators has been growing in recent years. Entries for this search were as follow: 21,900, all time; 1,330 in 2002 and 3,830 in 2011. In summary, interest for pollinators and their economic impact has been growing but at a lesser rate than interest on invasive species. So much for perceptions!

      I hope that you can support all your other statements better than this one.
      Beatriz Moisset recently posted..Gardening for Honorary Butterflies (Mint Moths)

      • says

        Beatriz, your logic here eludes me. A larger number of papers published simply means that more researchers are in a field than there were earlier. There are thousands of papers being published by genetic engineers and oil exploration geologists every year, vastly more than a decade ago. So doing more and more genetic engineering or oil exploring means that their work has a sound basis and is useful? No, it just means there’s more funding.

        The number of papers published in a field as well funded (by pesticide companies to a large degree) as invasion biology has nothing to do with whether many of their colleagues are questioning the assumptions underlying their work. This is the issue, and I, as well as Kevin Bayuk, have cited a few of the many places that these questions are being raised. The point is, more and more invasion biologists are understanding that their research has often been done simply to prove what they assume to be true (invasive species are bad), or to generate self-evident data, like all the thousands of biased papers showing that when “invasive species X” moves into a disturbed area, it replaces the pre-existing species, and therefore that is an invasion and loss of diversity. Of course, these same biologists are undisturbed when a single native species uniformly replaces an earlier diverse array. and there are far fewer papers describing this much more common phenomenon, It’s that kind of bias that I have trouble with. The basis for much of invasion biology’s assumptions are being questioned by the biologists themselves, and citing numbers of papers will not make that fact go away.

        • says

          Is the pesticide industry subsidizing recent work on Invasion Biology?
          1. At least half of the papers in Invasion Biology are about prevention or biocontrols. No financial gains for pesticide companies there.
          2. The rate of introductions and invasions keep growing and causing increased concern, hence more publications on the subject.
          3. You asked that we check “Invasion Biology Controversy”, which I did. To my surprise, most of the debate is not about the discipline itself but about details, methodology etc. I see no evidence that the foundations of this discipline are seriously challenged despite Marc Davis et al.

          In response to some of your other comments:
          You seem to believe that undisturbed ecosystems are immune to invasions or nearly so. Not quite, take the American chestnut, for instance, nearly eliminated from healthy ecosystems. There are many more. In fact, in some instances, the invasive species itself becomes a disturbance that causes other non-natives to penetrate the previously undisturbed ecosystem. There are even names for this: driver and passenger species.
          Extinctions caused by introduced species should not be the only parameter to consider. There are others just as important, for instance functional extinction, such as that of the American chestnut, the American elm and others.
          Some extinctions caused by introduced species have been documented, not just in islands as Guam and Hawaii, but also in continents. When the American chestnut was nearly wiped out (by pathogens introduced with non-native chestnuts), seven species of moths that fed exclusively on American chestnut went extinct.
          Eventually, introduced species become integrated with the rest of an ecosystem, yes. But it takes a lot more than the mentioned one or five hundred years. It may be more like thousands; or even millions of years depending on the magnitude of the disruptions and loss of biodiversity.

          You, obviously love nature as much as we do. You are deeply committed to undoing some of the old human mistakes such as mega farming and that is commendable. What I don’t understand is why you can’t see that the ever increasing introductions of species all across the globe are also a human mistake that could be, at least, mitigated, since it cannot be entirely stopped.
          Beatriz Moisset recently posted..Pollinator Conservation Short Course

    • says

      Hi Toby,

      If you’re still following this thread, I invite you to read my comment below, dated July 10, which includes a rather surprising response to your observations here, written by the guy standing in the hardy kiwi.

  10. Mary Saunders says

    Toby quite carefully answered the question about “what everyone can plainly see.”

    Everyone does not plainly see in the same way.

    My understanding of some principles of first peoples and of permaculturists is that stopping erosion is important.

    It was also important to groom to keep tinder from accumulating, but this was not done with chemicals from the oil industry.

    The European pattern that was similar was coppicing.

    The deeper question for me is not about the plants, but about the humans.

    First people were stewarding what the white people found here. The white people, mostly, just did not understand that.

    • says

      Hello Mary. I too am quite concerned about humans and their actions. Many of us “white people” are still choosing to “not understand,” as you say, or in some cases to interpret with a self-serving perspective, the realities of nature. The jury is still out on invasive plants, and I wish more permaculturists would stop acting as if they’re so clever, they’ve got it all figured out. I know it feels good to reject what seems like old-fashioned scientific data. But that does not make the new interpretations correct. Not yet. Please read my comment below, dated July 10.

  11. Mary Saunders says

    Here is an example of both permaculture diversity and supporting natives, but also of understanding the depth of interactions and what happens when an actor in the play dies.

    It is Connie VanDyke’s back-yard diversiculture, on a small lot in Portland, Oregon.

  12. says

    Fascinating post and discussion Sue. I cannot understand how anyone can think we are getting on fine with invasive plants. There is so much good in both camps . . . and we are after all one earth. There is always room for improvement in any dialogue or practice. Hopefully that will come about soon. It is great that you are opening and inspiring discourse.
    Carol Duke recently posted..First Days of Summer Walkabout

  13. Ruth Parnall says

    Yes, of course there are cut-over forests and disturbed soils. But around here in western MA the land that was cleared by 1830, mainly to raise sheep, and then abandoned, has grown into substantial forest, some of which has not been cut since then and much of which has been selectively harvested over the years and remains very productive for both humans and wildlife. And especially around here and in VT, there is a thriving use of it as the authentic edible forest – for maple syrup. The occasional but recurring canopy openings, created here and there by storms, allow various seedlings and saplings in all strata to get a burst of growth before the canopy closes again. I do not see an impoverished landscape but I see richness in species and habitat niches. In all of this area, the soil was certainly disturbed and reconstituted by glaciation, but since then it has been plowed in some places but mostly grazed or rearranged by tree tip-ups, nourished by leaf litter, and worked over by soil animals. Poorly conceived clearing and re-grading for homebuilding is currently the most disruptive practice.

    So on the whole, we have woodlands and forests (the difference is a matter of scale) that are growing and regenerating if they are not disrupted by shade-tolerant invading plants that tend to create monoculture by suppressing reproduction of all others. These particular plant communities seem to be well without more nitrogen from Berberis thunbergi or Eleagnus umbellata. Trees come and go, providing wildlife habitat as snags and as fallen wood, without the help of Celastrus orbiculatus to strangle and drag down not only dying but what would otherwise be living trees.

    These known invasive plants may be welcome on some homestead farms, but the problem is that they don’t stay put within one’s own property lines. Dispersed by birds or wind, they become easily established, dominant, and difficult to remove in places where they are not welcome. In my opinion, it’s actually an act of short-sighted self-interest to plant and/or nurture species that are likely to escape into a neighborhood sugarbush or timber stand.

    • says

      Yes, Miki, I have read Mr. Shapiro’s comments. And I repeat, in this discussion we are not evaluating RESTORATION efforts. That is a different subject. Here we are examining the wisdom of permaculturists’ freely using and promoting the use of non-native plants that are known to be invasive and harmful to established ecosystems. Permaculturists respond by quibbling over the meaning of “established ecosystem,” and claiming that it’s perfectly acceptable to import potentially invasive plants and animals into their gardens because humans have always moved plants and animals all around the globe, and humans are a part of nature and if you disagree then you’re being “anti-people.” None of these arguments, nor any of the many more I’ve heard yet, actually addresses the fact that, regardless of what we’ve done before, and regardless of how we deal with the mistakes we’ve already caused, anyone who claims to care for the Earth really should try to avoid making MORE mistakes.

  14. John Browne says

    Toby Hemenway stated: “But on further looking, we see that loosestrife is good at cleaning up pollution–that’s why it predominates, because the natives can’t survive in the new conditions. And it supports the full array of local insects.” Now, I have a predilection for specious reasoning; and this is an excellent example! If anyone happens to have met “the full array of local insects” personally, I’d be happy to hear from them. And, as a current member of the Wa Native Plant Society (and a board member of the King County Noxious Weed Control program) I look forward to discourse on a couple of the subjects in this post. ^..^

    • James C. Trager says

      I appreciate this thoughtful response, Toby. One thing though, as an entomologist, I observe rather plainly (to use a current term) that insect diversity in all major groups is very reduced in less diverse plant communities, such as those whose understories are dominated by buckthorn, or shorelines by purple loosestrife, etc. Looking down, I see Jon browne has also addressed this. Yes, loosestrife swarms with common pollinator species, but these cannot be said to be “the full array”.

      • says

        The statement on purple loosestrife is based on a peer-reviewed paper demonstrating that loosestrife supports the same numbers and species of native insects as adjoining native vegetation and as in other native wetland vegetation in the area. That’s what I mean by full array: equal numbers and species, and it’s the right term, if unscientific. Right now I am in Montana away from my library, and don’t have the citation with me, but I have a copy of that paper at home (he wrote, lamely).

        Many, many exotics support the same spectrum of local species as native plants. See the massive reference section of David Theodoropoulos’ “Invasion Biology: Critique of a Pseudoscience” (where that paper is mentioned).

        James, I agree that things that reduce diversity reduce diversity (sorry, can’t help myself). Native biologists often use circular logic like that, and selectively. When native Douglas fir invades native prairie and replaces it in solid monoculture, or native hemlock forms a closed, bare-ground stand, it is called succession. Nativists don’t bemoan the terrible loss of diversity in those enormous areas. But when a non-native does the same thing, it is thought of very differently. We are highly selective in how we are viewing this. A lot of what we see as a problem is a mental construct. A solid stand of rhododendron as an understory is beautiful. One of buckthorn is a horror. In 10 or 100 or 500 years the buckthorn will likely have a “full array” of local partners and be as natural in the landscape as any “native” species that arrived there 350 years ago when my ancestors stopped the Indians from burning (and, no, I don’t like buckthorn much either!). We’re just in an ugly, to us, transition that will be over in the blink of an ecological eye, like a few centuries.

        I’m not arguing that exotics aren’t involved in very upsetting and drastic changes in species composition. They often are, especially in areas still rebounding from massive clearing a century or three ago. Not as often as natives are, of course, since there are far more natives in most landscapes. But it’s illogical that we label the former as a problem, and when the same thing happens with a native, we call it natural.

        • GregMartin says

          Here’s a section from David Theodoropoulos’ “Invasion Biology: Critique of a Pseudoscience” concerning Purple Loosestrife:

          “Purple loosestrife (Lythrum salicaria) is ” an aggressive invader, it has displaced native vegetation and destroyed waterfowl habitat by forming dense, nearly monotypic stands” (Hight 1993). “[P]urple loosestrife, an aggressive Eurasian plant that can overrun a North American wetland and reduce its wildlife value to roughly that of a parking lot” (Bright 1998). The National Invasive Species Council (NISC) places it in their top ten invaders (at the time of this writing).
          Nevertheless, Anderson (1995) reviewed 34 papers on loosestrife and found records of 29 native species of wildlife using the plant, and many records of native species out-competing it. Many insects including native lepidoptera utilize the plant (Barbour & Kiviat 1997), and goldfinch (Spinus) nest in it (Kiviat 1978). In a study of 41 plots in Ontario, no significant differences in vascular plant species richness was found, regardless of the presence of purple loosestrife, no differences in number of introduced species, nor was species richness affected by increasing percentage of loosestrife cover. A number of native species were more likely to grow in plots containing purple loosestrife (Treberg & Husband 1999). Whitt et al. (1999) studied 258 plots over two years in purple loosestrife stands in Lake Huron wetlands, and found higher avian densities than other vegetation types at somewhat lower diversities, including ten breeding species in loosestrife dominated habitats. They conclude “that avian use of loosestrife warrants further quantitative investigation because avian use may be higher than is commonly believed.”
          Hager and McCoy (1998) “traced the history of purple loosestrife and its control in North America and found little scientific evidence consistent with the hypothysis that [it] has deleterious effects…Loosestrife was initially assumed to be a problem without actually determining whether this was the case…there is currently no scientific justification for the control of loosestrife…” Yet loosestrife is still touted as an “invader” – Pimentel et al. (2000) give it top billing and claim $45 million in control and loss costs in the United States alone, and the NISC features it prominenetly on their website (at the time of this writing). Further, the use of herbicide to control purple loosestrife “often results in short-term reductions, but the species reinvades within a few years, often in higher abundances than untreated areas” (Blossey et al. 2001; Skinner et al. 1994).”

  15. Susan West says

    Fascinating discussion. I’m just a retired organic farmer in Iowa and not all that familiar with exactly what permaculture is. But with that said it seems that any discussion of invasives on our plant Earth should include humans as we are the most invasive species of all. As a college instructor (of psychology I think) once pointed out, whenever we point a finger a someone/something else there are three fingers pointing back at us. Without recognizing/accepting humans as the most invasive species, that all residents of Earth are affected by all other residents, and that each species is equally important to a healthy ecosystem/Earth we will continue this argument without resolution. And that’s my two-cents worth.

    • says

      Hi Susan, and thanks for contributing to the conversation. I agree that humans might reasonably be called an “invasive species.” However, we at least, unlike all the others, have a brain and ought to use to it to minimize the harm we cause. If possible. And I know it’s incredibly difficult. Sadly, many of us seem to believe that we should use our brains to come up with clever rationalizations for causing more harm while doing whatever we want.

  16. GregMartin says

    Sue, first of all I just wanted to compliment you on hosting such a great discussion. So much of what an individual sees when they view a landscape is determined by their world view and discussions like this hopefully help us all with our human perception limits (and our ego issues).
    I’m writing concerning your comment above: “Hey. How about that. According to this oft-quoted expert, not only do invasive species exist, they also affect biodiversity.” In “Invasion Biology” Mr. Davis is clearly building the case with research that non-native species movement into new areas has affected biodiversity by INCREASING it. He points out that local patches may be heavy on the new plant, but that at larger scale biodiversity has increased dramatically and without extinctions.
    On the permaculture topic, permaculture plantings aim towards much higher species diversity than surrounding areas and surveys of insect diversity within such plantings, not surprisingly, also show much greater diversity. The practice of permaculture is generally a tradeoff of living in an edible landscape versus having a lawn (grassy monoculture) and acres of monoculture corn/soy/wheat 1000′s of miles away from which your food is trucked. Wild lands continue to be cleared for standard agriculture to feed a growing population and it’s easy to imagine that they will disappear with current practices. Meanwhile my land is thick with wildlife that’s drawn to my diverse food forest. The many bird songs filling my ears as I write.

    • Mark says

      Indeed, an interesting discussion. I try to use a variety of concepts and philosophies in my gardening endeavors. I do indeed have a broader variety of edibles than your average gardener, I suspect, including some *permie* plants, like comfrey, goumi, buffaloberry, peashrub, etc. Like Greg, I have noticed an increased variety of bird life and othe wildlife as I have decreased the grass and increased the edibles and related plants. I cut the autumn olive down…at least I have been meaning to do so. Here in Maine there is a quite active permie group and I personally haven’t witnessed the extreme positions you mention. Indeed, the basic philosophy amongst people in our growing group is that there is no single right or wrong way to garden. I try to follow the basic perennial edibles principles in many of my plantings, yet I do *square foot gardening* raised beds even to the extent of using a soilless mix in the raised beds for my vegetable gardens. On the permie side, I am actively encouraging a little stand of cattails that started growing on it’s own in a wet area. I’ve built a berm to h
      elp retain more moisture for the cattails. So, I am encouraging a native invasive species! Oh my! Thing is…cattail; is such a useful native plant, but it has received a bum rap. Have I intentionally planted a non native invasive plant with no consideration of it’s possible side effects? I don’t think so; But I’m sure that, in some areas a few things I have planted might be considered invasive. In my own experience so far, though, none of the species I have planted have been invasive in any way, though the comfrey I planted that was supposed to be Bocking 14 was not and I ended up with one volunteer comfrey clump. That has come in very handy!

      I guess, to summarize my point in this overly lengthy post of mine, no single philosophy of gardening fits every gardener’s needs. So, to each his/her own.

    • says

      I understand, Greg, the worthy goal of growing more food locally so as to reduce pressure on distant ecosystems. No one is disputing that edible landscapes are a great idea. The issue at hand here is whether or not those edible landscapes should include non-native perennial plants that serve our human “needs” at the expense of the health of surrounding natural ecosystems, whether immediately or at some time in the near or even distant future. I encourage you to read my comment below, dated July 10, to see what I’m talking about.

  17. says

    An interesting discussion which would have benefited from a rigorous definition of “invasive,” IMO. The author uses kiwi as an example. My personal knowledge of kiwi horticulture is limited to my father-in-law’s unsuccessful attempt to grow it on his acre of fruit trees and vegetables in the Central Valley of California. He was a serious gardener who enjoyed some success, so based on that experience I find it difficult to believe that kiwi is always invasive.

    In other words, the behavior of plants varies depending upon the local conditions about which we cannot generalize. Few are universally invasive.

    The definition of invasive is also a matter of opinion. USDA defines it narrowly. Only plants that cause economic or health harm are classified as invasive by the USDA. Therefore the USDA list of invasive plants is quite small.

    In the middle of the spectrum of defining invasiveness, California’s “Invasive Plant Council” classifies about 200 plants and trees as invasive. Some of those classifications mystify. For example, berry producing plants don’t actually spread in the garden, but because birds eat them and poop them elsewhere, they are considered invasive. So, the nativists demand the eradication of many plants that are useful to birds and other wildlife.

    I think I’ve found the extreme of the spectrum here in the San Francisco Bay Area. Our most prominent nativist demands that only plants which are known to have existed in 1769 in specific neighborhoods of San Francisco are allowed to remain. The National Park Service seems to abide by the same principle. And in our public parks, pesticides are being sprayed on benign plants such as scabiosa and sweet peas. These plants aren’t even on the long list of invasive plants of the California Invasive Plant Council. The City’s IPM program tells us that they are free to define any plant as “invasive.”

    So, “invasive” seems to be in the eye of the beholder. It is just a word that is used to justify spraying a non-native plant with pesticides here in the San Francisco Bay Area.
    Million Trees recently posted..More evidence that eucalypus is not flammable

    • says

      Thank you Million. As you and I both know, there can be no absolute definition for the word “invasive,” because its meaning depends on the context in which it is being used. There is also no absolute definition for words such as “health, youth, aging, stupidity, wisdom, ” and countless other terms that we use every day without controversy. I do realize that invasiveness is a complex subject. What is not complex is the simple reality that some non-native plants can have extremely destructive capabilities when released from the biologic controls of their habitat of origin, and we are well aware of that capability for several species, and when we continue to use those plants in our gardens despite our knowledge of their capabilities, we are acting immorally. Even beauty is in the eye of the beholder, to use your phrase, but we still know it exists. Please read my post below, dated July 10, to see just how real the invasiveness of hardy kiwi can be.

      • says

        Point taken. The arguments for planting are different from the arguments for eradicating. Admittedly I am primarily focused on the destructive methods used to eradicate plants which don’t seem to be doing any harm. As you say, planting with caution is a good way to avoid being forced to use destructive methods to eradicate.
        Million Trees recently posted..Vandalism by native plant advocates

      • GregMartin says

        Sue, the most difficult issue to me is the lack of ability to predict the future with what a plant will do, and for that matter what the environment will do. I have a lovely productive peach tree which is, of course, non-native and is thought to be a very well behaved plant. Likewise concerning my apple trees. Yet both are closely enough related to important native species that they could perhaps affect their genomes? Are they okay to grow? Also there is the potentially long lag time issue regarding when a plant is grown and when it somehow is able to start spreading and naturalizing into wild places (perhaps when a population of wildlife adopts the fruit as a food and starts to spread it’s seeds and the seeds with the right combination of genes take root?). How to know which, if any, non-natives are safe to grow? When a species does naturalize we know for sure, but that is too late. One plant in this catagory is Autumn Olive. It was widely planted by conservation groups because of it’s obvious value in feeding wildlife and restoring badly damaged soils. It was so valuable to wildlife and so good at growing in impoverished soils that it spread far and wide. Once it’s invasiveness was noted the USDA recommended it be only grown in areas where it has already naturalized to avoid it’s spread. If you live in such an area where the surrounding landscape produces untold millions of seeds is it really immoral to grow that plant for your own consumption and the improvement of your polyculture’s soil? I really do find this issue to not be so black and white. Meanwhile modern agriculture is responsible for wholesale loss of wild spaces and massive loss of the soils those places built up over 1000′s of years. Is it moral to stay dependent on and further spread that system when we can move to perennial polyculture systems that build soil and support wildlife? Please note that permaculturists did not introduce these species and are not the primary growers of most of these plants. Also know that most permaculturists (at least the ones I know) ARE trying to avoid the spread of known invasives.
        It seems that the reality of our times is that the columbian exchange has effectively brought the continents back together and we are in a reshuffling period. Here in New England introduced earthworms, fungi, honey bees and other insects have helped to restructure the wild environment in profound ways well beyond what plants are capable of. Globally we are having population booms and busts…not easy to predict what the final results will be. Not easy to predict how to be effective in the face of nature as she sorts this out. I kind of feel like permaculture is getting some scapegoat treatment here.

        • says

          I agree with you Greg: there’s a lot of fuzziness in these issues. And permaculturists are trying to make things better, that’s for sure. The issue of genome muddling is yet another layer of complexity! Anyway, I started out just trying to raise this one issue: couldn’t we, shouldn’t we, be careful and avoid planting plants that are currently known to be invasive? Many permaculturists already agree with this idea. But I see that it’s much more complex, especially in the minds of permaculture thinkers, than I had realized. My hope now is that this discussion, and others like it, will help us find more clarity about the whole subject.

  18. says

    To all commenters, especially those who doubt the destructive power of Hardy Kiwi:

    Here is IMPORTANT INFORMATION, excerpted with permission from an email I received from Tom Lautzenheiser, Regional Scientist for the Massachusetts Audubon Society. Mr. Lautzenheiser writes:

    “Toby Hemenway’s assertion that the hardy kiwi infestation that appears in the image (at the start this blog post) is growing on a human-caused edge is incorrect. I know that because I have been to the site; in fact I am the person in the image. Hardy kiwi is eating the forest at Mass Audubon’s Pleasant Valley Wildlife Sanctuary and adjacent lands like an acid, pulling down one mature tree after another. Over a period of decades, hardy kiwi has created gaps, or amphitheaters, in the forest, where the ground is covered with hardy kiwi vines 4 to 5 feet deep, and curtains cover the surrounding trees.

    “I have found hardy kiwi in all growth forms (seedling, to small patch on the ground, to one vine climbing a single tree, up to 3 acres of solid hardy kiwi infestation) in otherwise intact, mature forest, indicating that the vine can germinate and become established in shade. Within the amphitheaters are the fallen trunks or snags of the trees that have been pulled down by the weight of the vines (probably due to snow and ice loading or wind), proving that the area had been forested, and one only has to look at the surrounding trees to see their fates. In total, more than 15 acres of forest at the site have been destroyed by hardy kiwi, and that area expands as each additional tree succumbs.

    “The infestation of hardy kiwi in Lenox appears to originate from landscape plantings associated with the Hotel Aspinwall, which existed between 1902 and 1931 on the site now known as Kennedy Park. While much of the forest in the hotel’s vicinity also was generally established around this time (based on current forest composition and structure), hardy kiwi also occurs in older, undisturbed forest areas a mile and more away from the hotel site.”

    Mr. Lautzenheiser also kindly passed along an image from Bing Maps, showing the extent and location of the disturbance created by the invasive hardy kiwi. Take note: there are no roads or other disturbances anywhere nearby, no edges that nature must now press hardy kiwi into service to “heal.” Any land that almost a hundred years ago may have been open and “landscaped” has been developing steadily since then into a mature hardwood forest. Except now here comes hardy kiwi, charging back to life after a long “lag phase” of inaction. Here is the link to that image:

    To those of you who see or learn about this site and say, “Well, that’s just one little piece of land,” I say: wake up. This is DATA about the amazing capability of hardy kiwi. We don’t need to read a book to understand it; we can just use our own eyes.

    For those who still wonder about what and where hardy kiwi grows, here is a link to an “Invasive Plant Pest Alert” fact sheet:

    In closing, I again ask all permaculturists (and all gardeners and landscapers, for that matter): Would you please consider the potentially destructive capabilities of non-native perennial plants that you, either innocently with all good intentions, or stubbornly despite all warnings, bring into your gardens. What will happen when you are gone from your land?

    • says

      I have said several times that the shade-tolerant vines are very challenging species, so I’m not surprised to see Mr. Lautzenheiser’s report. And I’ll repeat that all of New England is a highly disturbed landscape – perhaps in this case the forest has had a century or so to begin rebuilding a few of its interconnections after clearing and farming, but what Mr. Lautzenheiser calls ‘”mature” looks awfully young by ancient-forest standards. I’d wager that New England had nothing like it 500 years ago; it’s likely a new, post-disturbance assemblage that has plenty of open niches in it, begging for new species to fill them.The vines will come, and they will go. After all the alterations in the landscape Euro-Americans have made, it’s going to be centuries before we stop seeing things like these kiwi amphitheaters. We cannot predict when a species will turn rampant – next time it might be string beans – so we have two choices: never, ever introduce a new species, or accept that we are dealing with new types of ecosystems that are going to make us miserable if we keep thinking about the impact of new species as a disaster. The first is impossible.

      Very relevantly, I spent last Saturday in the Beartooth Mountains with a retired local ecologist. We stopped at a disturbed site in the sagebrush above Red Lodge and he harvested two bouquets of plants, one of natives, one of exotics. The exotic bouquet had at least twice as many species in it, including a number that he was pretty upset with. He is no fan of invasive species. Later we stood in a mixed-conifer grove high in the much less disturbed mountains, and he showed the immense damage from the pine beetle, a native insect that is devastating millions of acres in the west. It seems to have burst out of control because of decades of Smoky the Bear fire suppression – our way of saving the ecosystem – that has left the forest full of crowded trees that are perfect beetle food. This is a native species that has gone rampant. This happens all the time: many thousands of acres of lodgepole pine in Idaho and eastern Washington are dying from native honey-mushroom infestation, but ecologists are starting to understand that this may be a way of returning nutrients to the soil after old-growth forests have sequestered them above ground for too long. We hate to see these forests die. And we don’t know what’s going on.

      When someone asked what we can do about all this, the ecologist answered that we can preserve very small areas in special projects, but that anything beyond that is simply impossible. The impact of non-native species, he said, brought here in the massive quantities that they were and still are, combined with our alterations in the landscape of a whole continent, make any return to previous conditions out of the question. We don’t like this, he said, because it holds a mirror up to us and shows us how out of balance with the rest of nature we are. And now we’re stuck with the consequences, so we demonize the other species instead of facing what he sees as the real problem: there are too many of us, moving around far too much. Asking people not to plant species that they like is a losing game, not with a hundred million gardeners in this country shopping at nurseries.We’re going to have to learn to live with this new landscape, as much as we don’t like it, and take it as a stunning opportunity to learn about ecosystem development, was his conclusion. It is a colossal experiment in hybridizing whole ecosystems, and to say “this species is bad, or this one” misses the point completely. We have altered a continent and there is no undoing it, no return to before. We cling to the hope of preservation and restoration because we can’t accept that we have to live with what we have done. It’s time to move on, he said, accept that these species are here, and stop interfering. We didn’t know enough to keep this from happening, and we surely don’t know enough to “fix” it. The attempted cures are doing even more harm, the way fire suppression did. Thinking it is a problem is the problem.

      He struck me as a wise man, in many ways, and I learned a lot from him. I’ve been spending many days in Yellowstone this summer, and see that one simple restoration act, re-introducing the wolf, has slammed through that nearly undisturbed, enormous ecosystem in hundreds of unforeseen ways. The elk have been driven out of the valleys into the hills. The bison are exploding through the valleys, along with once-scarce pronghorns. Species mixes of all kinds are shifting in totally unforeseen ways. It was a profoundly radical act that has totally altered the landscape, all because of one management decision. And we think we know that hardy kiwi is wrong to be there? We need to stop deciding we know better than nature, even nature with kiwi in it.

      Am I saying we should do nothing? Well, we can do what we want, and I’m sure we will. But it won’t make much difference at all, except where we’re able to target especially vulnerable species and habitats and freeze some of them where they are (in ways nature never does). Nature is just too big, the process too far along.

      I was at a conference a while ago called “Native Plants and Permaculture” where those two groups came together to make peace and learn from each other. We did an exercise where everyone lined up where they thought they fell along a spectrum from “Only plant natives” to “Plant whatever you want.” There were 3 people in the first category, and one in the latter. Everyone else, permies and nativists, were mixed in a perfect bell curve with most right in the middle. Our difference are tiny. Let’s stop focusing on them.

      Again, I think that against all the good that permaculturists are doing, it makes little sense to focus on the tiny minority of us who don’t think before we plant. That’s a minuscule drop in the bucket compared to corn, GMOs, nursery owners, developers, and all the others who alter land and plant exotics. It’s a classic case of making our firing squad in a circle, as Che claimed the Left was prone to do. The discussion of all this is very fruitful, but the accusations that permaculturists are doing significant harm, compared to all the others, don’t hold up.

      Most states have invasive species lists in the several hundreds, which to me says we’re either completely doomed or there is an error in our way of thinking. In another 5 years another hardy kiwi-like enemy will appear, and then another, and another, with no one able to predict, like the native pine beetle, what it will be. You can be miserable about this if you want; I’m going to watch it and learn from it. We have no choice but to wait out the next few hundred years until this terribly unbalanced landscape finds some new, always-dynamic set of equilibria. Meanwhile I’ll be using the best tools available (and they won’t include hardy kiwi in New England!) to create healthy designed ecosystems in the places people are settled in, and if nature chooses to use something I’ve planted for her own purposes, in a way that I don’t understand, I will accept that she knows what she is doing instead of thinking, always wrongly, that I know better.

  19. says

    Sue has stated repeatedly that the issue at heart is “whether or not [permaculturist’s] edible landscapes should include non-native perennial plants that serve our human “needs” at the expense of the health of surrounding natural ecosystems, whether immediately or at some time in the near or even distant future.”

    So while we have danced all around that question, in very fruitful and informative ways, let me try to answer it directly.

    First, we’re not planting to serve human needs exclusively or even primarily. Every permaculturist I know was drawn to it by a desire to serve nature better. Our plantings are designed to be highly multifunctional, to support (as my book says) the rest of nature while nurturing people too. I think we can do both, and we have to, or we will tear apart the planet with industrial farms.

    This is what it boils down to. All of us in this discussion are trying to reduce the human footprint, and I think permaculture’s multifunctional, ecology-driven approach is a better way than to plant natives and then shop at Costco, or even Whole Foods or the food co-op.

    Permaculturists, many of us former natives-only enthusiasts like Jono and me, have come to the conclusion that a garden full of a diversity-rich array of wildlife supporting, soil-building, insect-attracting and otherwise beneficial plants, some of which feed and otherwise support the people living there while doing so much else, is much less ecologically damaging than to have a yard full of grass, or native plants, or to shop at the store for your food, or even to grow a monoculture of vegetables in bare soil. It’s a question of relative damage: We’re all doing damage. I think permaculturists are doing less than almost anyone else. Other people’s damage is out of their sight, while they can see our autumn olive growing, so they target us.

    We also think that even if one of our plants turns out to be invasive and contributes to a short term loss of diversity or alteration of an always-changing landscape, the benefits of our multi-functional landscapes in total outweigh the harm. They do this by reducing the pressure on the conversion of wild land into corporate monocultures, by providing habitat for many, many native species, and by all the other ecosystem services they perform. The benefits of a garden full of inedible natives, while significant, to me seem completely offset when that native-plant lover buys a box of granola and in so many other ways commissions the conversion, out of sight and therefore not taken into account, of wild land into ecological desert, estimated to be about 6 acres per American. If I can pull my footprint down to 3 or 4 or even 5 acres by practicing permaculture, I think the planet is better off. If somewhere out there is a 2-acre patch of hardy kiwi with my name on it, it’s doing a lot more good, and is much more temporary, than a 2-acre monoculture of corn with yours on it.

    Thanks for all the fun.

  20. says

    It seems that Sue and some of the others are cycling the same thing over and over again. You should read what Jonathan wrote above:
    “ is impossible to understand or address ecological function and health separately from human social function and health. Given the size and spread of human population, the impact of human technologies, and the imperatives of (existing) political-economic arrangements, no meaningful area of Earth’s living systems is independent of human effects. This means that, to address ecological distress we must necessarily simultaneously address human needs (whether biologically or socially determined), and vice versa, as they are unavoidably linked.”

  21. says

    Well, what a lively discussion. Sue, I have also experienced plenty of rudeness from workshop participants on this issue, though from the other side. Perhaps those of us in leadership positions in our movements might encourage an attitude of respect and courteousness towards other branches of the environmental movement. In my workshops I’ve been strongly emphasizing the links and a great area of overlap between the native plant and permaculture areas of interest. For example, you can visit my website to see my list of useful native plants of the mid–Atlantic region and useful native cacti of Mexico. I’d like to see our movements spend more time talking about useful native plants like blueberries and getting more of them into gardens ,and less time picking at each other’s fringes. If we did so we might accomplish a number of shared goals. I believe this overlap in our goals is actually a very large and deeply interesting area.

    With that said, like some others who have written here I don’t love hearing my movement being called one of the worst types of agriculture. And as I said in my chapter to which you referred, I think that a native plant garden is not sufficiently ecological, in that if your food is being shipped in from halfway around the world you’re simply externalizing that ecological cost. So I believe there are cases for conversation about the responsible growing of plants which have been labeled “invasive” when we take into account the reduced carbon footprint, fossil water use, and other ecological costs that they allow us to offset. Apparently you disregarded or didn’t care for my arguments in my chapter and didn’t care to give them a voice in your article.

    Finally, here is my specific quote from Davies: “Nature is continually changing, but it does not have a goal. Nor is there only one valid nature that can or should exist at a particular place and point in time. As individuals, and as a discipline, we need to find a place in this operational continuum where we are able to work towards remedying harm where it truly exists, without becoming compulsive and parochial in our perspectives and behavior, without mistaking change for harm.” (Page 188, invasion biology, Mark a Davis, Oxford University press 2009”. I would encourage you and others in the native plant movement to visit with part three of Davies’s book in which he reflects on invasion biology as a science and proposes some major course corrections to get back in line with the rest of contemporary ecology. Again, as I mentioned in my chapter.

    I do welcome this conversation but I’d like to see us have the decency of quoting each other accurately and looking for the good intentions that are indeed at the heart of both of our perspectives. And I offer you the challenge that I’ve been giving (mostly in jest) to native plant enthusiasts lately: when you grow and eat as many native plants in your garden as I grow and eat in mine (45), you have the right to criticize what I grow. But without understanding the real limitations of our native edible flora and its state of domestication, it can be difficult for some people to appreciate why permaculture turns to plants from other regions. I’d be happy to send a list of native food candidates from your region to anyone who would like to inquire, or those of you from the eastern forest can turn to the hundreds of native edible plants listed in volume two of Edible Forest Gardens, which I co-–authored with Dave Jackie.

    Eric Toensmeier

    • says

      Hi Eric, and thank you so much for writing. You’ve given us much food for thought.

      I would like to make two minor corrections about your assertions. First, in my original post, I wrote that permaculture was, in the way its use of invasive plants seems to place human wishes and desires before the health of the natural world, “LIKE the worst systems of agriculture and horticulture.” While this point may be debatable, I did not actually call permaculture one of the worst systems of agriculture. In fact, as I’ve tried to make clear in numerous comments, I believe permaculture offers many great benefits to the world, and gives us all a lot to think about. In this discussion, I have learned that many many permaculture proponents do feel an imperative to use native plants in their gardens/farms, either predominantly or exclusively, according to their own preference.

      Second, I took your comments about changing the word “harm” to “change” from a chapter you wrote in Thomas Christoper’s book “The New American Landscape.” I did not notice that you were referencing Mark Davis. My own reference to the Davis book came in the next sentence, in which I mentioned the widespread use of this source as confirmation of the new way of thinking about invasive species (So far, about 100% of the permaculture proponents who have written in have referred us to Davis’s writing). You mention a “Davies” quote, and I’m not sure what you’re referring to…. unless you mean that same Davis book. Anyway, I don’t believe I mis-quoted you.

      All in all, I continue to be a bit puzzled by how one of the most common permaculture responses to concern about growing invasive plants comes in some version of a statement about how much food you are eating from your own land, thereby reducing your ecological footprint in faraway agriculture, and how that makes you somehow entitled to grow invasive plants. I’ve heard this so many times now, and I really don’t get the connection. Just being virtuous in one way really does not give us permission to cause harm in some other way. Does it? I know, I know, you’re going to say “invasive plants don’t cause harm, they help the earth heal from the harm we’ve caused.” Yep, I get that. I’m listening really hard to the arguments, and trying to be open to this new way of interpreting natural events. A lot of smart people accept it, so maybe there’s something in there that I need to learn. And I hear that some scientists are bringing us new data about non-native invasive species. (I also know that many scientists continue to show us data about harm from invasive species, and many scientists disagree with Davis’s conclusions.)

      What I don’t understand, still, is how anyone can defend, sometimes quite aggressively, actions that have any potential to cause harm, since we still don’t know absolutely that these new interpretations are correct. My point is: why take any chances?

      The whole issue of how carelessness about invasive plants might ultimately undermine the permaculture movement is really not mine to evaluate. I will say, though, that a friend in Australia who uses permaculture principles in his garden was deeply shocked to hear that some Americans consider it okay to garden with invasive plants.

      (PS: I’ll bet your co-author Dave Jacke would probably love it if you spelled his last name correctly.)

      • says

        I’m afraid my voice transcription software has a few bugs in it. Yes, I meant Davis, and thanks for pointing out Dave’s correct last name – oops!

        The connection is that all-native, non-edible gardens ALSO cause harm in that they don’t provide our needs, and those needs are typically provided in ways that damage the environment. I’ve yet to hear native plant gardeners really address this.

        Given that any non-native plant could potentially become invasive (e.g. kiwi springs into action after over a hundred years), if we leave ourselves only native plants to eat that’s not a great diet. And I’m a big fan of native plant foods, but most are simply not yet ready for prime time. Thus we arrive at our conundrum.

        It’s great to see your perspective evolving, and I’ll say this dialogue helping my perspective evolve as well. Particularly regarding hardy kiwi, which I do dearly love but those pictures are a more than a little scary.

        I’ll not rant on with lots of points that have been made but just say its good for us all to be having this discussion.
        Eric Toensmeier recently posted..All Nitrogen Fixers Are Not Created Equal

        • says

          I totally agree. My understanding is expanding also.

          Regarding the non-edible landscape issue…I have never suggested that all food should be native. That would just be nuts (ha). My concern is only about permaculturists growing perennial food crops that have the KNOWN capacity to naturalize and cause disturbances in local ecosystems. I do sort of wish we could also avoid gardening/farming with all non-native perennials simply because we just don’t know what they’ll do in the long run, but I know that is crazy idealistic/unrealistic.

          I also have an uncomfortable reaction to the oft-stated permie claim that because they’re growing food and thereby reducing damage to some distant environment, that makes it okay for them to do things that cause harm in some nearby environment. It sort of sounds like, “I don’t beat my kids, so therefore I’m entitled to kick my dog.” The two things don’t really add up, at least not in my mind.

          Thanks for writing back~

  22. says

    Here are hard data on introduced plants that have rapidly formed partnerships with native insects, from a paper, “Exotics as Host Plants of the California Butterfly Fauna,” by Sherri Graves and Arthur Shapiro, in Biological Conservation (2003) 110:413-433. It was sent to me by Mary McAllister, a SF blogger ( concerned about wholesale removal of healthy exotic trees from large swaths of rural SF-area parks. Other ecologists questioning the wisdom of natives-only policies are Mark Davis, Dov Sax, Erle Ellis, Matt Chew, and Peter Del Tredici, if you want to find papers by them. There is, indeed, widespread criticism of invasion biology by biologists.

    Dr Shapiro is an ecologist at UC-Davis. His findings:

    In 1925, California had 292 species of naturalized exotic plants. In 1993, there were 1057. So about 75% of California’s exotics have been there less than a century. Yet overall, 32% of California’s native butterfly species are now feeding or breeding in non-native plants. Some specifics:

    Yellow star thistle, a noted pest plant, is a major nectar source for many central valley and foothill butterflies. Eucalyptus is a major roosting species for Monarchs now that native trees have been decimated by logging and development along Monarch migration routes. Eucs may have prevented great reduction of Monarch populations. (I’ve seen a photo of thousands of Monarchs in a Euc.)

    Marshland butterfly species, greatly reduced by development, have increased again by breeding and feeding on introduced wetland plants, and these non-natives stay green longer than the natives once did, allowing extension of the breeding season. These introduced hosts may have been critical for the survival of wetland butterflies decimated by development. In at least two, and possibly more cases, exotics allowed other butterfly species to extend their breeding from 2 to 4-6 or more generations per year, helping their populations rebound.

    In the city of Davis, 29 of 32 butterfly species breed on introduced plants. 13 of them have no known native hosts in Davis at all. This suggests that introduced plants have prevented the extinction of local butterfly populations in developed areas. Alfalfa and vetch fields have been colonized by at least 12 species of butterflies, with extremely dense populations.

    Shapiro shows many other cases where native butterflies are feeding and breeding on introduced plants like Cork oak, passionflower, Bermuda grass, Senna, Rumex, as well as Monterey pine outside of its natural range. On the downside, Shapiro noted two cases of butterflies breeding on exotics that were toxic to larvae, wasting those breedings. But the overall finding was that many species of introduced plants could each support many species of insects, and individual species of insects were able to feed on multiple introduced species.

    There are many papers like this. Multiply this California paper on one order of bugs by 50 states and all the insect orders, and you have thousands of insect species relying, critically, on thousands of introduced plant species.

    What is interesting here is that, like Doug Tallamy, Art Shapiro is an entomologist, yet the two come to opposite conclusions based on hard data. I think the data support both: native plants are critical for insect health, and exotics have rapidly co-evolved with many species of native insects for critical support, especially in cases where development has destroyed local hosts.

    So I think it’s time to start dialing down the rhetoric about exotics breaking up native-species partnerships. In fact, to me this raises an irony. This paper shows that when development or farming has eliminated native hosts, removal of large areas of introduced plants can destroy the only available hosts for native insects. So I’d like to turn around the whole question raised by this blog: We have absolutely no evidence that permaculturists (as opposed to, say, nurseries) have ever introduced a species that has later escaped into the wild from their planting. That’s just a “what if” scenario with no support for it, so, quoting Beatriz: “Where are the DATA” for this assertion?

    But we know very definitely that natives-only people have removed from large areas, wholesale, valuable host species, like Eucalyptus, star thistle, and many others. Dr. Shapiro and many others have expressed abhorrence for this very damaging practice: See

    Permaculturists, unlike nativists, are not going into wild and semi-wild lands and exterminating valuable host species. Permie don’t have the kind of hubris that says we know what’s best for wild land (we have other forms of hubris!). We restrict our activities to planting valuable wildlife species in yards, farms, and other highly developed areas. We’re taught to stay out of the bush, as Mollison says. That is a far more conservative and safe action than messing around in the wild.

    I think we can safely conclude that native plant enthusiasts have done far more damage to native insect populations than any permaculturists, real damage at scale, versus hypothetical damage. And I am grateful to this blog for the irony of helping to point that out.

    Look, we’re all human, and we tinker with things we don’t understand, as part of our nature. Permaculturists are learning from nativists that it’s a bad idea to plant introduced species known to be local “naturalizers,” to use a neutral term. And I hope the nativists (and I am a native plant lover) will learn that it is equally unwise to exterminate naturalized species, because the roles of those species are not understood, but are known now to often be critical hosts to many natives. We have a lot to learn.

    • says

      Thank you again Toby for your ongoing contribution to the conversation, but geez Louise, how many times do I have to write that I am not talking about restoration policies and their various wise or unfounded justifications? And I don’t think anyone else here, besides the permaculturists looking to dismiss native plant proponents’ concerns, is either.

      I know you’re enjoying your time on the giant soapbox you perceive this blog to be, but really, couldn’t we stick to the subject?? It seems to me you have already agreed with me that planting species that are known to be eager “naturalizers” (as you call them) is, in general, a bad idea and an action that most responsible permaculturists would eschew.

      I’d also like to point out that in one sentence you call others “nativists” (a term meant to be vaguely insulting), and immediately following that you call yourself a “native-plant lover” (a much more reasonable label that I think all native plant lovers would prefer). Does that seem fair? I enjoy your wide-ranging examination of this issue, and yes we all have a lot to learn, but come on, the slurs don’t help.

      • says

        Sue: I don’t see nativist as a slur, any more than permaculturist, Buddhist, artist, or any other -ist indicates anything more than a brief way of describing an aficionado of something. And you invited me back into this discussion via personal email after I had left, knowing I was a wordy old windbag already, so lay off the soapbox charge, speaking of slurs (written actually in good humor – we’re human.)

        Here’s the crux. You’ve made the charge that permaculturists are doing harm by planting invasives. I’ve responded that:

        1. Few permaculturists are doing this.
        2. I don’t recommend doing this.
        3. When it is done, the known, measurable good of healing damaged habitat and reducing human footprint outweighs the hypothetical, unproven “damage” done by unproven, hypothetical escape from a permaculture site.
        4. Escape of introduced species does a fraction of the damage that native-plant lovers (there!) claim – and is often extremely helpful given the critical support played by many exotics when they enter (as in virtually every case of their escape) damaged or altered habitat.

        The last point is important to make (and Beatriz, Kate, and others insisted that it be demonstrated) because combined with the others, it satisfies me, if no one else, that you have made a charge that is unsupportable, though it engendered fruitful discussion. Sorry that it took me so long to get around to that tidy summary, but there it is, finally.

        My conclusion is that, unlike native lovers tearing up whole landscapes, permies wrecking the landscape with exotics is an unfounded charge, so unlikely that it is not worth worrying about, but unfortunately, zombie like, it continues to be resurrected. I’m hoping this is a stake through its heart.

        • says

          Got it. I was trying to be funny, but I guess it didn’t work.
          I do still think that the words nativist and purist are generally only used by people aiming, subtly, to diminish others. They are not simple descriptors like artist, pianist, soloist, etc. I know of no native plant lover who calls him- or herself a nativist, because of its obvious negative connotations. However, that minor point aside, I do hear you. And I will check out Mr. Shapiro’s findings.

    • says

      I see no discrepancy between Tallamy’s and Shapiro’s results. In a nut shell, Shapiro shows that non-native plants are better than a concrete jungle devoid of plant life in feeding certain native insects. Tallamy takes it a step further and demonstrates that a landscape composed predominantly of native plants supports more insects (both in biodiversity and biomass) than a landscape made mostly of non-natives. And as a consequence it also supports more vertebrate wildlife. Perhaps Shapiro had no way to do such sort of study. Also, you should remember some of Shapiro’s conclusions: “Increasing occurrences of exotic host use are expected and those species not capable of shifting to nonnative hosts are likely to have higher vulnerability to extirpation and extinction in the future.” Of course “increased occurrence of exotic host use” is due to increased rates of species introductions. It seems that we all agree that this process is detrimental to some native species, the ones unable to shift.
      Beatriz Moisset recently posted..Gardening for Honorary Butterflies (Mint Moths)

      • says

        I have read Tallamy’s book, Bringing Nature Home, and Shapiro’s publications. They are not saying the same thing.

        Tallamy claims that native insects use only native plants. He provides no scientific evidence to support that claim because he says that the studies have not yet been done that would prove his claim. He provides anecdotal “evidence” based on his own garden in which he claims that the insects are only eating his native plants.

        In fact, there is considerable scientific evidence that refutes this claim. Shapiro’s study is only one of many such studies. I won’t repeat the extensive description of that study which Toby provides, but will instead tell you about several others.

        Scott Carroll has studied the transition of the native soapberry bug from a native to a nonnative tree. This transition took about 20-50 years and involved physical changes such as the length of the soapberry bug’s jaw and the timing of its hatch. The original “version” of the soapberry bug did not change because its original host did not disappear. The soapberry bug is not very mobile, so the result was two different populations of soapberry bug living on two different host plants in different locations. In other words, the introduced plant increased biodiversity, which is often the case.

        Dov Sax (Brown University) compared the species richness of the native oak woodland with the eucalyptus forest in Berkeley, California. He found equal number of species of insects, amphibians, rodents, understory plants, and birds. In that same study he reports similar studies all over the world, because the eucalyptus has been introduced all over the world for a variety of practical purposes. These studies found the same result when comparing the introduced forest to its native neighbors. The only caveat to that generalization is that the introduced forest is equally biodiverse after about 5 years.

        The fact is, adaptation occurs more quickly than native plant advocates would like to think it does. This is not new information. Darwin reported the specialization of the finch’s beak on different islands within a few generations. Why native plants advocates don’t consider this good news, is a mystery to me.
        Million Trees recently posted..Permaculture takes the long view of the big picture

        • says

          Oh, sigh! You didn’t read my answers to Jono on the other Permaculture blog when he made the same objection about Tallamy’s work. So, please read my article, “The Science…” ( To get a little background, you may also want to read about host plants, generalist and specialist herbivores, plant toxic defenses and herbivore adaptations to chemical defenses. You may want to borrow an ecology textbook from the library; even Wikipedia, despite its limitations, may prove useful.

          Both, Shapiro and Tallamy have done fine scientific work. The issue is that they posed different sets of questions and, naturally got different sets of answers. It isn’t that the results are in conflict; they just deal with different aspects of nature. Some herbivores can switch to other food plants, especially if they are generalists and if the plants belong to related taxa with similar chemical defenses. Examples of this abound. Specialists don’t fare so well (Shapiro is aware of that). This affects the entire food chain.

          What Doug Tallamy set to test is: Can alien flora support the same numbers, variety and biomass of herbivores than native flora? The answer is: No. Does this impact the vertebrate biota (birds, for instance) that feeds on insects? The answer is: Yes. Shapiro did not study that. He doesn’t know whether the butterflies that feed on non-natives in a totally altered environment would do better on their favored host plants if the plants were there. Also, he doesn’t know about the entire herbivore insect fauna on the non-native landscape. Perhaps, such undisturbed habitats are not available to him anymore, or perhaps he is not interested in finding that out. That is fine. But it is important to compare native and non-native landscapes: which ones function better as ecosystems, which ones are better for wildlife. That is what Tallamy focuses on. None of the studies you mention tackles this issue.

          As for Darwin’s finches; it was a very rapid evolutionary process. It took around half a million years, which is a blink of an eye in evolutionary terms. No comfort to us, though.
          Beatriz Moisset recently posted..The Yucca Moth and the Yucca

          • says

            I am familiar with the argument about specialist vs generalist insects. The claim that insects that have made the transition from native to non-native plants are generalists is not consistent with the facts. Professor Art Shapiro reports that 26 of the 82 species of California butterflies now feeding on exotic plant species, are using only one plant species. In other words, nearly one-third of California butterflies presently using exotic plant species are not generalists.

            When butterflies have made the transition from a native to a non-native plant, the plants are usually chemically similar, as Beatriz says. However, this principle is one of many about which Tallamy is mistaken. He states on page 48 that many of our non-native plants are chemically unique and therefore native insects are unable to make use of them. One of the examples of such chemically unique non-natives which Tallamy provides to prove his point is the Golden Rain Tree. In fact, this is the very tree that the soapberry bug is now using, having made a quick transition from its chemically similar native host tree.

            Tallamy also states on page 52 that only 10% of insects are generalists. He is mistaken. Most insects are generalists and the principles of evolution would tell you why. Natural selection does not favor animals that are dependent upon only one plant, for obvious reasons. Nature is dynamic, the climate is constantly changing and plants that are adapted to one climate are not necessarily able to survive such changes. If an animal is dependent upon one plant, its chances of long term survival are greatly diminished. Mutually exclusive co-evolution is therefore very rare in nature because it is a risky strategy which often leads to a dead end.

            As for Tallamy “doing great science,” his book readily admits that there is no science associated with his speculation about the dependence of native insects on native plants. On page 53 he says in answer to his own rhetorical question, “How do we know the actual extent to which our native insect generalists are eating alien plants? We don’t until we go into the field and see exactly what is eating what. Unfortunately, this important but simple task has been all but ignored so far.” Once again, Tallamy is mistaken., This work HAS been done by many scientists and what they report is not consistent with his assumptions.

            Now we have an update on this important question, straight from Tallamy, who is quoted in an August 2011 interview with the Garden Rant blog: “He convinced one of his grad students to make a study of insect damage, comparing “traditional” with all-native landscapes – six of each. After two years, the result was that only a tiny percentage of leaves were damaged on EITHER of the properties, with 1.5% of the leaves showing sucking damage and 4.5% chewing damage, both far below than the 10% damage threshold shown to be needed before homeowners notice it. And the difference between the native and mostly-nonnative landscapes was statistically insignificant.”

            Now we know, directly from Tallamy, that when insect damage in the garden is used as the measure of the usefulness of non-native plants to insects, THERE IS NO MEASURABLE DIFFERENCE! Since Tallamy set that up as the test of his theory about the dependence of insects on native plants, we can safely conclude that the theory is mistaken.

            One final issue, having to do with the speed with which evolution occurs. Those who read the book, The Beak of Finch, will know that the changes in the beak of the finch as it moved from one island to another was observable in the lifetime of the humans on the islands. Clearly not “half a million years.”

            And on this question, we can also turn to Tallamy as another indicator of how central this question is to the native plant ideology. On page 44 Tallamy tells us that evolution is very slow and that insects can only use plants “to which they have been exposed for thousands of generations.” (page 52) But, on page 75, Tallamy claims exactly the opposite when it suits his ideology. He explains that non-native plants are not invasive immediately, but become invasive as they “evolve and adapt to a new environment in 80 years.”

            There are many other contradictions in Tallamy’s Bringing Nature Home. I am just describing the contradictions upon which Beatriz has commented. I have been debating native plant advocates for 15 years, so I know I won’t change her mind. I am speaking to anyone who has not yet made up his/her mind. If you made it this far, thanks for listening.
            Million Trees recently posted..Permaculture takes the long view of the big picture

  23. says

    Dear Million, or Mary McAllister:

    Thank you for your comments. I did read them all the way to the end, and in response I have a few questions for you. Most of them are a bit rhetorical; the last one is not.

    Can species adapt to the changes they encounter? Yes. Can they evolve to have a new shape or new abilities or new body processes, allowing them to coexist with new species? Yes. Can species manage to continue surviving all the challenges we throw at them? Clearly, yes, some can. Some may adjust relatively quickly, some may take too long for us to see or know. Yes, nature will survive. But even if Mark Davis’s assertion is true that invasive species have caused no extinctions (a negative claim that is actually impossible to prove), do you know how many species struggle and ail, and what it costs them? Nobody can know this.

    The calculations behind whether or not to attempt to remove invasive species that have become established in “novel” ecosystems are complex and morally difficult (and that issue has never been the subject of this blog thread, despite commenters’ persistent efforts to change the subject to match their own argument.) To my mind, however, there is nothing the least bit morally complex about whether to bring MORE non-native species into places where they have not been before.

    The fact that some species CAN adapt does not give us the right to REQUIRE them to adapt.

    How dare we humans keep being so arrogant and careless?

    • says

      I agree w/ everything you say. As I’ve said before in this thread, the arguments for planting species are entirely different from the arguments for destroying other species. I always urge native plant advocates with whom I debate to plant whatever they wish. I ask only that they quit destroying everything they don’t prefer.

      The reason why I request that they quit destroying non-native species is that the methods used to destroy them are clearly doing more harm than good. Our urban public parks are being sprayed repeatedly with powerful pesticides such as tyclopyr, imazapyr, and amino-pyralid. Such powerful pesticides are clearly not beneficial to the wildlife that native plant advocates claim they are benefitting.

      And the millions of trees that are being destroyed are storing millions of tons of carbon which will be released into the atmosphere as carbon dioxide when they are destroyed and as they decay. Carbon dioxide is the predominant greenhouse gas which is contributing to climate change. The ranges of native plants have changed in response to climate change and they will continue to change. Exacerbating climate change does not benefit anyone, including native plants and animals.

      Because of the very real and significant damage that is being done to our environment by native plant “restorations,” I react to the arguments used to justify them, such as the scientifically unsupported claim that insects are dependent upon native plants. And when I see such claims, I cannot resist providing the evidence that they are mistaken.

      Echoing your concluding sentence, “How dare we humans destroy the homes and food of wildlife and spray their homes with toxic chemicals! How can we be do arrogant and careless?”
      Million Trees recently posted..Permaculture takes the long view of the big picture

      • says

        I agree with you completely about avoiding using toxic chemicals. I myself am not qualified to speak knowledgeably on the subject of restoration methods, although I suspect that, like with most things, the topic is more complex than most of us realize and the “best” solutions vary greatly from site to site. The trouble with citing scientific findings is that so much of what we believe, and choose to do, ultimately comes down to a question of our values.

  24. Cletus says

    Ecology has two broad divisions, autoecology (study of individual organisms and species) and synecology (study of the interactions between organisms). Part of the reason why we don’t have the kind of data we need to judge these ecological phenomena with adequate complexity is because synecology has been historically underemphasized and is still in somewhat of an embryonic stage. If you read Dr. Robert Ulanowicz’ publications, you see that autocatalytic feedback is at the core of ecosystemic logic. Autocalysis means every element effects an increase in every other element(indirect mutualism). Ecosystems self-select/self-organize this ideal network arrangement. If we understood the whole of the autocatalytic synecological relationships well enough I’m confident that we would, in many cases of rampant species causing a monoculture or apparent decrease in biodiversity, see over time a definite increase in nutrient cycling and soil health and therefore biodiversity. Now we still have to overlay this with our own goals and timescales to make judgements about what kind of planting or management approach we want to take. For example, massive acres of dead trees resulting from an Armillaria blight might not be something we would promote, but over time complexifies the ecosystem into a forest/grassland mosaic with much greater richness. We need to respect the autocatalytic thrust toward complexity. Also, it is logically shaky to compare soil loss, groundwater mining, and toxification from today’s agricultural practices to what plants/animals/fungi do in spreading to occupy an open niche in a new ecosystem.

  25. Tomas Sharif says

    Hello Folks

    It would seem wise to look into indigenous diets of each ecosystem that consisted of native plants. There are any number of good books or sources that can be researched on these matters.

    Two sources to suggest would be Buffalo Bird Woman’s Garden by Gilbert Wilson and a number of books by the Shaker communities who preserved in their writings wide varieties of native plant food sources.

    It seems a simple matter to use permaculture methodology applied to a native plant dietary system and all folks should prove happier for it as well as a healthier ecology.

    There is a centuries old climax forest at Lilly Dale N.Y. that is well mapped perhaps that would be one place to begin.



  26. says

    You say “European buckthorn, favored by permacuture as a nitrogen-fixer”. I think that you may have the wrong plant. Permies favor sea buckthorn (Hippophae rhamnoides) not European buckthorn (Rhamnus cathartica). If you google “European buckthorn”permaculture, you will see many discussions dealing with discouraging it. In fact, the first hit you get – – is about its invasivenss and the damage it does. If you google “sea buckthorn”permaculture, you will see many discussions talking about incorporating it into the design.


  27. Tomas Sharif says


    The Following is a quote by Buffalo Bird Woman, Hidatsa Native American gardener, on the effects of weeds brought by European influences:

    “We Hidatsas did not like to have the dung of animals in our fields. The horses we turned into our gardens in the fall dropped dung; and where they did so, we found little worms and insects. We also noted that where dung fell, many kinds of weeds grew up the next year.

    We did not like this, and we therefore carefully cleaned off the dried dung, picking it up by hand and throwing it ten feet or more beyond the edge of the garden plot. We did likewise with the droppings of white men’s cattle, after they were brought to us.

    The dung of horses and cattle raised sharp thistles, the kind that grows up in a big bush; and mustard, and another plant that has black seeds. These three kinds of weeds came to us with the white man; other weeds we had before, but they were native to our land.

    Our corn and other vegetables can not grow on land that has many weeds. Now that white men have come and put manure on their fields, these strange weeds brought by them have become common. In old times we Hidatsas kept our gardens clean of weeds. I think this is harder to do now that we have so many more kinds of weeds.

    I do not know that the worms in the manure did any harm to our gardens; but because we thought it bred worms and weeds, we did not like to have any dung on our garden lands, and we therefore removed it.”

    Best Regards


  28. Frank Landis says

    Speaking as a “Nativist” (member of the California Native Plant Society), I’m actually quite offended by the idiocy of permaculturalists who use that term. Now that your back is about as far up as mine was with that stupid nativist label (most of us prefer conservationists or preservationists, thank you!), let’s talk some sense, and use California as an example.

    There are two things to know about California: one is that we’ve got a growing native plant horticulture industry. This trade only involves 1-5% of the California flora, but the driving force is xeriscaping: California has a notable lack of water, and a lot of native, gorgeous, drought-adapted plants. Yes, there are redwoods and monterey pines too, but most of the growth is in xeriscaping.

    Then there’s the paradox of the California Indians. In Indian times, corn-farming made it as far as the Colorado River, which is only about 30 miles from the California Floristic Province (on the ocean side of the mountains, for those who don’t know the term). Corn grows in California just fine, but why did the Indians not adopt corn like everyone else did? The answer is that native plants, such as oaks, Calochortus, various pines, and so forth, produced so much food that there was no reason to plant corn. Moreover, California’s climate is notoriously unstable, and it’s saner to have a plethora of native species to depend on, rather than praying for rain that may well never come. Modern California agriculture depends on a massive irrigation system to move water from where it snows to where it’s needed, and Indian Corn culture stopped at the last reliable summer water: the Colorado River.

    Now, I’m not going to advocate for going back to the California Indians’ system. We can’t because their form of permaculture supported 1-10% of the population we have now. Permaculture? Absolutely. Kat Anderson documented California Indian land and plant management practices in her book Tending the Wild, and I’ve seen the remnants of the edible landscapes the Indians produced to feed themselves. For example, there’s one slope on Santa Catalina Island that’s so crowded with edible plants that you can’t avoid stepping on them, and that’s 150 years after the Indians were removed to a mission.

    Where the permaculturists have utterly, miserably failed in California is that no one (to my knowledge) is documenting the permacultural uses of native plants! It’s absurd, with an exclamation point! To pick one example of many, you can find native plant honeys in markets all over the state, and California buckwheat (Eriogonum fasciculatum) is a reliable bee plant that grows throughout much of the state and blooms six to eight months of the year. It’s also a plant that is at risk from climate change in the wild, and it’s extremely easy to grow. Why foster yellow star thistle when you can plant California buckwheat? I use buckwheat honey in my Christmas cookies, because it tastes so much better than clover honey.

    So, rather than permaculturalists whining at the conservationists who kill weeds in wildlands for very good reasons, why not investigate the uses of the thousands of native plants that the conservationists are trying to save? There’s already a growing native plant industry there to supply materials for your experiments, and the plants are no more expensive than are the exotics permaculture currently favors.

    As for weeds, yes, I’m a weed-killer. I target species like Italian thistle and smilo grass in my favorite preserve, because I’ve seen no evidence of any animals using them, and they’re crowding out plants that the animals do use. I also chop the heads off of cardoon, so that the rabbits can kill them later in the year. Despite what the books say about cardoon being a soil builder, where I work, cardoon leaves don’t decay for years, unlike the native around them that decay within a year or two. If this isn’t what you’re expecting, realize that CNPS weeders aren’t indiscriminate. There are exponentially more weeds than there are people to deal with them, and we work on situations where we can make a positive difference.

    • Sue Reed says

      Wow, Frank, thank you so much for your thoughtful comments. I didn’t know that fact about corn in California. Fascinating! I appreciate your very practical approach to managing weeds, and I am especially in favor of permaculturists learning to place a higher value on cultivating native edibles. This is all part of a gradual shift in public attitudes, and I am always happy to discover others whose philosophy is similar to mine!

      • says

        Sue, your statement “I am especially in favor of permaculturists learning to place a higher value on cultivating native edibles” says that you need to learn far more about permaculture. Google permaculture”native edibles” to see what I mean.

        • says

          Dear Mike H.
          I may indeed need to learn more about permaculture, but your belief that all permaculturists already place a high value on growing natives is naive. I have talked to many of these folks, and I have myself seen many permaculture gardens, and a vast majority of them do not place a high value on growing natives. In fact, they either disregard or entirely reject the notion of native species, asserting instead that every plant has a right to be planted anywhere we humans choose, simply because nature (which, in their thinking, includes humans), have been moving plants around for millenia, hence it must be acceptable (despite that fact that human transport of species around the planet for our own desires and “needs” has been the cause of tremendous harm). And, they ask, who are we, mere humans, to claim that we know what is best for nature? And they say, “you native plant advocates are just sentimental nativists, fools and wrong-headed in every way,” and they feel free to hurl insults at those of us who approach gardening and landscaping from a perspective that places a higher priority on the needs of the natural world and its inhabitants than has customarily been the case throughout human history. From my perspective, permaculturists continue to act as if the imperative to feed and clothe humans must take precedence over all else, and they use this attitude to justify growing horribly invasive plants wherever they please. I find this attitude offensive and incredibly self-righteous and exactly just as short-sighted as agriculturists throughout history. So, it really doesn’t matter how much I google native edibles. I’m sure you are right that many permaculturists are already growing native plants. But many are not, and these are the people I am concerned about, especially when they are some of the most vocal among your group, and they appear to have the ear, and faith, of a lot of gullible followers.

          • says


            I don’t want to get into an argument with you here so I’ll not comment on any of your statements. FWIW, it seems to me that corn, soy and wheat are three of the worst invasive species that we have when it comes to displacing & destroying the natural world and its inhabitants. How many of us recognize that?

  29. SOPHIE says

    Thank you for writing this article. I always think of permaculture as being the perfect ideal and it’s sad that people have forgotten the main principles. Nature knows best, we need to listen to it.


  1. [...] in the permaculture community, prompting Sue to write another post where she posed the question “Why is human benefit the only issue that seems to matter to permaculturalists?” Why aren’t we also promoting healthy ecosystems that support [...]

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