What Native Plants Like Clay Soil?

American hornbeam is an attractive understory tree for clay soil.
Photo: Lady Bird Johnson Wildflower Center

It seems that conversations with gardeners, if they go on long enough, will turn to the topic of clay soils:  how difficult they are, how to fix them, or how to live with them.

Native plants are true multi-tasking tools in the landscape:  they reduce pollution, provide habitat for wildlife, and supply gardeners deal with solutions for difficult site conditions – including clay soil.

So, what are good native plants for clay soil?

This will, of course, depend on where – precisely – you live.  Generally speaking, however, you are looking for plants that can tolerate two particular conditions.

One is that true clay soil can sometimes contain very little oxygen relative to other soil types.  Clay, by definition, is a soil with very small particle sizes and these small particle sizes form a tight soil with few pores between.

Winterberry holly provides great benefits to birds, and brightens up the winter garden.

Winterberry holly provides great benefits to birds, and brightens up the winter garden.

Another is that clay soil provides challenging moisture conditions.  On the one hand, they don’t drain especially well and so they can be very wet.  On the other hand, in drought conditions they clay particles bind very tightly with water molecules leaving little moisture available for plants.

As a general rule, both of these conditions are similar to ones found in poorly drained flood plains, river bottoms, or marshlands.  Look for species that naturally grow well in areas that alternate between drought and flood.

Here are five species native to Maryland that I think work very well in clay soil.

Asclepias incarnata, or pink milkweed. This perennial is also known as swamp milkweed, which should be a clue to it’s suitability.  It produces attractive pink blossoms in summer which are attractive to pollinators, and is a host plant for Monarch butterflies.

Iris versicolor, or blue flag iris. A native iris with extensive roots, this plant is drought tolerant once established but also very happy in excessively wet soils.  Because of its massive root systems, it is also very effective at filtering pesticides from storm water.

Clethra alnifolia, or sweet pepperbush. Sweet pepperbush has upright clusters of fragrant white flowers and dark green leaves that turn yellow in fall. This shrub blooms in early summer, when few other plants are blooming, and a large stand of clethra is a veritable magnet for pollinators.

Ilex verticillata, or winterberry. This is the time of year that winterberry really shines:  bright red berries on the female plants of this deciduous holly brighten the garden in fall and winter and provide an excellent food source for migrating or over-wintering birds.

Carpinus caroliniana, or American hornbeam. This small tree is a great choice for dense soils.  The foliage is very attractive in fall, and is a food source for swallowtail butterfly larvae.  Seldom exceeding fifty feet in height, this is a valuable understory tree.

Given that soils take thousands of years to form, it is usually unrealistic to expect that homeowners can amend clay soil sufficiently.  If you want to try, incorporate organic matter (like compost or wood chips) NOT sand.

Best, though, is to simply ask yourself “what native plants LIKE clay soil” and build your garden around those plants.  Native plants that like clay soil will be less work for you, and better habitat for wildlife.

© 2012 – 2013, Vincent Vizachero. 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.

Related Posts Plugin for WordPress, Blogger...

Don’t Miss the Wren Song Community

Wren Winter Singing crop

Free Exclusive Content and Member's Forum

Sign up for a free membership in the Wren Song Community and you'll have access to a lot more valuable information published exclusively for our members.

Meet other passionate wildlife gardeners from around the country. Share your successes. Learn from your failures. Discover the best resources to help you create welcoming habitat for wildlife in your gardens with native plants so that you will attract more birds, butterflies, native pollinators, and other wildlife to your garden.

Learn more about the Wren Song Community

Comments

  1. Pauline Horn says

    While I admit anyone who lives in a house built in the last sixty years was left with clay soil (because the builders strip the existing top soil and sell it.), I think there is something you can do about it, although it takes a long time, so your list is certainly necessary. Starting twentyfive plus years ago, I got rid of my lawn and replaced it first with ivy (because I didn’t know any better) and then with native trees, shrubs and perennials, and most of the natives that were planted by squirrels and birds. I spread mulch every year, but I also leave the leaves in place every fall, along with the dead stalks of perennials. After more than twenty years I now have soil that is as black as woodland soil. I don’t fertilize except when I first plant a plant or I see symptoms of lack of nutrients. Admittedly this is a long term project, but it’s also much easier than the usual maintenance – mowing fertilizing, raking, etc., and is much better for the environment.

  2. says

    Many prairie plants are clay tolerant, and from seed will take 2-5 growing seasons to send their extremely complex root systems into the soil that partially die annually adding organic matter into the clay soil. Prairies take 25-100 years to reach their maximum soil carbon sequestration, and with clay soil it would take longer, but clay soil prairies are a natural ecosystem, and can be ornamentally, or naturally mastered using native prairie plants adapted to those soils.

    My quick suggestion list:

    Prairie dropseed
    Compass plant
    Pale purple coneflower
    Little bluestem
    Big bluestem
    Switch grass
    Saw-tooth sunflower
    Maximillian sunflower
    Purple prairie clover
    Rattlesnake master
    Western sunflower
    Stiff goldenrod
    and there’s plenty others that would together create a beautiful clay tolerant landscape.
    Solomon Gamboa recently posted..Part. 2 – Floral Clock Prairie Seeding

  3. says

    Honestly, I took to dumping topsoil, mulch, and composted cow manure/mushroom compost on top of the stuff and planting in that. I’ve got a few beds now that will support life, but the straight clay was too much even for the legendary “clay-busters” like cup plant and big bluestem. (They don’t die, but they don’t get any bigger either.) Building what amounted to about a four inch raised bed on all my planting surfaces gave everybody enough decent dirt to get established, and the layers of mulch (and exuberant earthworms!) has started to soften the clay layers under it and make them a bit more friable.

    It’s still bad in a few spots, but it’s far better than when I started. You can’t do much when the developer’s stripped your dirt off, alas.
    UrsulaV recently posted..Ninth Day of Christmas

  4. says

    All is not lost! Clay soils have some redeeming qualities too!
    The surface of clay soils tends to become extremely hard forming a cap over the moist soil below so established plants, especially of tap-rooted species survive extreme drought. Clay also maximizes plant access to potassium, magnesium and calcium and is nutrient rich. Mixed with rocky soils and/or compost, clay can become a very workable soil for many plants. For those of us in the West who deal with clay soils most of the time, finding plants that are amenable to it is really important. Here’s my short list:

    Pasqueflower
    Fringed Sage
    Arrowleaf Balsamroot
    Sticky Geranium
    Lupine spp.
    Prairie Smoke
    Rocky Mountain Juniper
    Bitterroot
    many Penstemon sp.
    Chokecherry
    Snowberry
    Yucca

  5. Don Schaffer says

    Previous owners put down black landscaping materials everywhere, leaving soil. Leaving soil below dry, hard,heavy dense. Took a post hole digger to plant annuals in ground. What do u .recommend?

  6. says

    I’m blessed with very heavy clay soil here in Philadelphia, and sometimes I despair that the only things that do well are things like Sweet Autumn Clematis, English Ivy, Bishops Weed, and so many other invasive plants. Last summer I ripped the whole garden out, and will start over again in the spring. This list is a great starting point, Thank you :)
    Carole Sevilla Brown recently posted..Ecosystem Gardening Essentials

  7. Dee says

    I have clay soil here in the Chicago area. Usually, when I plant anything, it’s a lot of extra work. I try to dig down as far as I can, & remove as much of clay soil as I can. I then fill in the hole with composted manure, then plant & back fill with more composted manure.
    After all this work, the roots of the native plants still travel down into the clay soil. Bee Balm, Incarnada Milkweed & Liatris Ligulistylis have done well in the clay soil. I’ll be ading Milkmaid Milkweed this summer, & I expect that to do very well in the clay soil.

Leave a Reply

Your email address will not be published. Required fields are marked *

CommentLuv badge