‘planting in a post-wild world,’ with thomas rainer

Post-Wild_CoverWE GARDENERS want to do the right things: to attract pollinators, for instance, or grow more natives, and be environmentally conscious. We also want to create gardens that work for us, that are manageable—and resilient—even in tough situations and changing times. But goals like “sustainable landscaping” or “ecological landscape design” can sound a bit lofty and theoretical to those of us without a landscape-architecture degree.

Landscape architect Thomas Rainer is co-author with Claudia West of a new book called “Planting in a Post-Wild World” that inspires us to design plantings that function like naturally occurring plant communities. It also instructs how to manage them, not doing painstaking and often impractical garden maintenance, plant by plant, as in traditional horticulture. (Enter to win a copy of the book in the comments box below.)

Washington-based Thomas Rainer teaches planting design at George Washington University, and has designed landscapes for the U.S. Capitol grounds; the Martin Luther King, Jr. Memorial; and The New York Botanical Garden, as well as more than 100 private gardens. He is also a keen—and daring–home gardener.

I welcomed him back to my public-radio show and podcast. Read along as you listen to the Sept. 21, 2015 edition of my public-radio show and podcast using the player below. You can subscribe to all future editions on iTunes or Stitcher (and browse my archive of podcasts here).

Thomas Rainermy q&a on ecological design, with thomas rainer




Q. Can you distill for us the idea of “Planting in a Post-Wild World,” which is also kind of your design philosophy?

A. I had been in a practice for many, many years where we were doing a lot of high-end residential garden design. It was great—I loved the immediacy of that. But I always had large maintenance crews to follow up on my planting designs. When you have clients with large budgets and really good gardeners, I think your understanding of how well you design plantings can be a little bit inflated—which I think happens.

I swapped; I kind of had my Olmsted-ian itch and wanted to get into a firm that does much more large-scale public parks, public landscapes, embassies—I love that scale, love projects that affect a larger group of people. But they are the types of projects that sometimes have budgets to plant once, but not to maintain them.

And Claudia was dealing with the same thing—a lot of municipal designs, a lot of rain gardens. People with the very best intentions, but not always the kind of budgets or the kind of knowledgeable maintenance crews that I’d had previously. It left us in a place where we had a lot of projects that looked great for the first year, and then really fell apart.

Both of us were really wanting to be sustainable, we wanted to be beautiful–we had all the goals that I think a lot of home gardeners have. But we really wanted to understand how to put plants together in a way that actually was a little more resilient–in ecological terms, but also just in maintenance terms for crews like that.

For us, the post-wild world is the fact that we don’t have as much wildness in nature as we once had, and that trend doesn’t look like it’s changing. But there is a lot of space around us—in cities and in suburbs. The landscape architect Gilles Clement calls it the “third territory,” all the little remnants of green you have in cities—the medians, the roundabouts, the backyards, the public-library spaces. The sum total of all that space is fairly large, even though it’s a confetti of isolated green spaces.

I think our attention is turning more to those areas—what is planting design, and how can we make it really functional for those types of landscapes, and not only for high-maintenance ones?

Q. Last time we spoke on the show, Thomas, we focused a lot on the native vs. exotic debate, which can become very contentious. This new book doesn’t get into arguing, arguing, arguing but is very positive. It’s a very optimistic view about designed plant communities that are inspired by naturally occurring ones. You get your inspiration from nature, even in the post-wild world.

by Thomas RainerA. That’s right. And the inspiration isn’t only the beautiful native-plant communities you see hiking in the Shenandoah Valley or these great National Parks. There is a neighbor across the street, kind of a hippie, who doesn’t do much with his yard, and has this sort of “hell strip” along his sidewalks, filled with weeds [above]. I remember at one point going over—and it’s probably 2 feet wide within a 10-foot segment, so 20 square feet—and I counted 26 different species of weeds growing in there.

I started thinking about that density and diversity of plants growing in there, in something that just spontaneously emerged. It wasn’t beautiful at all—it looked like a weed patch. But I had nothing like that in my own garden, in terms of density and diversity, in any 20 square feet I had.

It was really remarkable to see how many species were interweaving together. So whether it’s these pristine, beautiful native inspirations or just how weeds really grow together, we started thinking there is a difference between the ways plants grow in our garden and the ways plants grow in the wild—whether it’s urban wild, or wild wild.

We wanted to really understand if there are some principles on how plants grow together that could inform garden planting—inform landscape planting, design planting, in a way that would be very practical.

There is a lot of ideology around native plants and we’re strong proponents and heavy users of native plants. But at the end of the day we really wanted just some practical solutions to some of the problems that we faced on a daily basis.

Q. In nature, whether in the post-wild world or in the Shenandoah, what you don’t see is something like a 3-inch-tall mown lawn and 100-foot trees as the only two elements. You see layers, staggered layers, like that hell strip across the street from you. You see different plants of different sizes and purposes and root system structures fitting together and making a community.

A. That’s right. All the plants are adapted—what we mean by “community” is that all the plants are roughly adapted to that environment. You can’t have an Agave next to a wetland iris; they’re not compatible in terms of the habitat.

The other element is that all these communities—whether a meadow or a forest or woodland edge—is that they’re layered vertically. The shorthand:

There are lots of different layers, and I think one of the things we worked hard on—because every community has different layering systems—was really trying to translate layers in ways that were applicable horticulturally, not just ecologically.

The big takeaway was that in almost all these naturally occurring plant communities, they had kind of a ground-holding matrix of plants. A meadow: Everyone can see the taller grasses, or the flowering forbs. But when you really get down to what’s at the base of some of these taller species, there are lower grasses, there are horizontally spreading rhizomatous plants—a number of different species actually hold the ground underneath.

p017__062 05-17-09_MBOr in the forest floor, the same thing happens with sometimes low woody species, or spring ephemerals or ferns and sedges.  There is always this layer, unless you’re in the desert or Antarctica or something—in most temperate climates, nature abhors bare soil. [Above, from the book: mayapple under an oak in early spring.]

Nature will fill bare soil, usually with plants. That was a big takeaway for us. The idea of mulch, in the American sense. We use a whole lot of bark mulch, that essentially forms the groundcover layer, because we know if we leave nothing there the weeds will come in or the soil starts drying out. We really think it’s possible—not only possible but possibly lower maintenance—if you replace this layer or the dependence on this layer with low, shade-tolerant plants that are compatible with more upright species. Not that mulch is not valuable.

Q. In the book you call this layer “green mulch.” Living mulch.

A. Yes, green mulch—plants. There are a lot of functional benefits from it. It does keep the soil from drying out and releasing carbon dioxide. The sunlight hitting the soil will degrade the organic matter much quicker than if it’s covered. Functional benefits: I’m a big perennial gardener, but we all know that perennials change so much in the course of a year. If it’s a warmer-season perennial, there are early times from March to May when the ground’s pretty bare. So balancing cool- and warm-season growers so you are always covering the ground.

In the groundcover layer, diversity becomes very important in terms of having many different root structures and competitive strategies : clumping plants, creeping plants. And as many different textures. It’s really a plant’s shape—its morphology—is how it really forms a reaction to other plants in the wild.

You know a massive Echinacea in the wild might flop over or look funny, but the whole shape of an Echinacea, for example, is meant to grow out of grasses. The whole stretching form, the low basal foliage—it’s all an adaptation to the community it’s supposed to be around.

Q. To its neighbors.

A. The more different shapes you have—it’s like a jigsaw puzzle in a lot of ways on the groundcover layer. The more different shapes you have, the more that can interlock. In a lot of ways, because these plants are so low, diversity doesn’t always mean chaotic plantings. In the upper design layers, you can still have some levels of massing, or some patterns. If you can cover the ground in the lower layers, you have a lot of flexibility to what you do design-wise in the upper layers.

So for formal gardens, maybe you do want to mass those upper layers more cleanly, so there is more intentionality and pattern to it. In a more naturalistic garden, maybe you’re expressing the ground-plane layer more heavily and the upper levels just get dotted in, some low grasses.

That’s what I really like about this idea: You don’t have to become a naturalistic gardener to have better vertically layered plantings.

p245T_cb-luz-0009_CBWe have one image in the book [above] of this fantastic mix of plantings in Germany, in a very formal, 300-year-old Greek Revival-looking house. I think a mix of maybe 20 species of perennials are in the middle of these garden beds, that are meant to have different waves of color from May all the way to November. It’s fairly mixed, but they had this beautiful boxwood parterre around the edge of it. They put an orderly frame around the mixed planting. All of a sudden, what might have been without that frame a very messy, wild, naturalistic piece looks totally appropriate with this very formal, historic garden.

We’re excited about the adaptability of this idea of layering, because it’s not so much about a style—we’re not advocates of a style. It’s really about some better functional ways of creating ecological combinations instead of just color combinations.

IMG_0480Q. There’s one diagram in the book [above] that has the three primary layers that you highlight and tell us to think about. You’ve mentioned the “green mulch.” Can you tell me about the others?

A. The other two are kind of more the design layers, the things you see at the top. One category we really like is kind of a mid-height layer. You have the groundcover layer, and then next is what we call a “seasonal theme layer,” and this would be masses or drifts of plants that have a long season of bloom, and really carry a seasonal moment. So maybe irises in the spring, or asters in the fall, or Asclepias (the butterfly weed) in the summer.  Different mid-height clumping plants that become part of the groundcover layer part of the year—become part of the background green—but when they bloom they really light up the whole garden.

Q. Right.

A. There are some really exciting designers in Europe. Heiner Luz, and I think the work of Cassian Schmidt does a lot with this layer. They’ve designed these mixes of 20 to 40 species for public parks, and even though it’s really highly mixed and the plant list looks chaotic, there is only one or two things blooming at one time. You have these high moments—one high moment rolling into the next high moment. The stuff that goes green isn’t visually dominant; these other things come up.

That’s really the seasonal theme layer: mid-height plants, clumping plants—but you’re really trying to think about the big seasonal swell stuff, like asters in the fall or iris in the spring.

And then the uppermost final layer would be the structural layer. In a mixed planting even those these are your trees or shrubs, in a meadow planting these could be things like your taller grasses—your Panicum, Miscanthus, the bigger Andropogon. Some of those really tall Rudbeckia maxima. Those really become structural in a meadow planting.

These are not necessarily numerically dominant, but they are visually dominant. So in a forest the trees and shrubs are some of the bigger elements that give it its boom. In a lot of ways you want this to be very simple; a lot of repetition in this layer can help calm down the diversity in the lower layers. The repetition of a tree creates the feeling of a grove even though you might have a dozen woodland ephemerals and sedges and ferns on the ground plane.

Or the repetition in a woodland setting of rhododendron or azaleas, in key places, gives the sense of calmness, even though at the lower levels there is a lot of diversity. I think what’s fun in this idea is that playing with proportions of the different layers can create very different effects—from very calm effects to much more vivacious, highly mixed looks.

Q. Fireworks. [Laughter.]

A. Fireworks—exactly.

by THomas Rainer from HermannshofQ. You mentioned Germany in one breath. This approach in the new book is rooted in various sort of ornamental-horticulture adventures in Germany starting in what, the 1980s?[Above, planting at Hermannshof garden in Germany.]

A. One of the great things about teaming with Claudia, who is from Germany originally, is that she is able to translate some of these great resources—mostly German, and some Swiss. Really since the 1980s on they have been trialing what they called these mixed perennial plantings, and the whole idea is that they have come up with entirely novel plant communities.

These are not groups of plants that grow together anywhere in the world, but they have taken the most ornamental selections of say, a Mediterranean-type climate. So the best Mediterranean ones might be some of the California annuals mixed with some of the western Australia perennials, and they’re recombined them into these perennial mixes.

The other thing I love about the German approach is that they’ve trialed these mixes for 10 years or more. For designers it’s a little scary, because the whole purpose is to eliminate the need of a designer whatsoever. They really want to democratize perennial planting. They’re intended for roundabouts or public parks—the kind of sites I deal with on a regular basis in which people want perennial planting, color, diversity for pollinators—but they don’t really have the know-how to make it happen.

So they give people the list, and the plants are already assorted into the different layers. You put them out totally at random, and it doesn’t really matter where you place the stuff because there’s a proportion and you kind of randomly plant them. They’ve had really remarkable results; some of the published photos of these medians and roundabouts where the maintenance level is very low is really impressive.

Q. And the drama, the ornamentality, is really high.

A. They have a high bar for color, yes. A lot of the mixes have color themes.

Q. There is sort of this mantra in the book, and your work in general, about management, not maintenance–quite different from the stuff I end up crawling around on my hands and knees doing all day in my horticulturally motivated garden. But maybe more like what I do where I manage my upper meadow. What the difference between maintenance and management?

A. A maintenance approach focuses on a different set of prescribed activities for different plants. I have a perennial border that’s not at all a designed plant community, and I know which plants need to be staked, or which ones are water hogs, or which need to be trimmed off the path. That’s a lot of my activities—a different set for different plants.

When you move from an individualistic approach to horticulture to this community approach, you’re really thinking about managing—the task is for the entire mix of plantings. You’re not doing something different for one plant (though you can always do a little bit of that).

Generally the activities are based on once-a-year cutbacks; it’s based on making some adjustments yearly to your seasonal theme layers that may be pooping out and you need to add more of that. It’s really looking at moving maintenance away from an individualistic approach to doing coarse actions aimed at the whole mix.

That can really decrease the amount of maintenance on a planting, particularly with lowered water use. I just have a small perennial border, but I spend a ton of time staking in some types of years, and a good bit of time pruning things away because it’s next to some paths. So if you have the mix designed for the space and for the site, a lot of those individualistic actions almost become irrelevant.

I was talking to the director of the Lurie Garden in Chicago. One of the things they’ve gone to for their annual cutbacks of perennials is to use a mulching mower once a year. That big annual cutback was a huge task for them, and they’re moving more toward broad-scale ecological approaches to managing these mixed plantings.

Q. More like I would do with my meadow, where once a year I mow it, the first week in May, and mulch up and rake the debris, and then go in twice in the growing season and rogue out or cut down to the base any Rubus—any raspberry or blackberry or other woody invaders I see. And that’s it.

enter to win ‘planting in a post-wild world’

Post-Wild_CoverI’LL BUY A COPY of “Planting in a Post-Wild World,” by Thomas Rainer and Claudia West for a lucky reader. All you have to do to enter: Comment in the box at the very bottom of the page, after the last reader comment, answering this question:

Are any ares of your garden based more on the idea of a plant community than a traditional horticultural design? Are you “managing” rather than “maintaining” any of your landscape (the way I am with my upper meadow compared to beds near the house)?

No answer, or feeling shy? Just say something like, “Count me in,” and I will, but an answer is better. I’ll select a random winner after entries close at midnight on Sunday, September 27. Good luck to all.

(Photo credits: Images from “Planting in a Post-Wild World,” by Thomas Rainer and Claudia West, except mayapple photo by Mark Baldwin; German boxwood planting by Christa Brand; Hermannshof meadow by Adam Woodruff.)

prefer the podcast version of the show?

MY WEEKLY public-radio show, rated a “top-5 garden podcast” by “The Guardian” newspaper in the UK, began its seventh year in March 2016. In 2016, the show won three silver medals for excellence from the Garden Writers Association. It’s produced at Robin Hood Radio, the smallest NPR station in the nation. Listen locally in the Hudson Valley (NY)-Berkshires (MA)-Litchfield Hills (CT) Mondays at 8:30 AM Eastern, rerun at 8:30 Saturdays. Or play the Sept. 21, 2015 show using the player near the top of this transcript. You can subscribe to all future editions on iTunes or Stitcher (and browse my archive of podcasts here).

  1. Leslie B. says:

    Finding plants that “play nicely together” is an intriguing challenge in a semi-urban Midwestern garden. This book will be invaluable, I’m sure! Thanks for educating us.

  2. Lisa says:

    I have a california poppy meadow that shifts to major mulch area in the late DRY summer. Slowly adding some perennial grasses to extend the seasons. This bed isn’t watered, even though it is in a dry mediterranean climate. My goal is to eventually have it look great yearround.

  3. Barbara says:

    Loving epimedian as a ground cover around bushes. Had liked strawberry begonia, but it gets robe too much and needs to be weeded out a bit and controlled.

  4. frederique jennette says:

    This book seems to challenge the gardener into looking for an alternative way of planting. It looks very interesting and he is also a good writer.

  5. For 10 or more years I have wrestled with a 60×8 foot bed that started as a traditional perennial border. It has evolved to rocky Mountain juniper and other mid-sized evergreen, deciduous shrubs and a few peonies, poppies and leopard’s bane and lots of shredded bark mulch. I wish I had read about this technique years ago. I have another bed (15×8′) that needs to be redone (for the fourth or fifth time) and I would like to use this technique for that area. My husband and I do all this ourselves and I wonder what we will do as we get older so a way to make maintenance more manageable would be very helpful.
    P.SO. I really enjoy your blog.

  6. Lee Kinzer says:

    I am probably “managing” somewhat the whole front of my yard, doing some weedeing, perhaps watering once a year, letting interesting things that show up have a chance (sometimes wonderful and sometimes a very bad idea!), and generally letting my plants (mostly but not all natives) duke it out. The result seems to be a wild landscape with a number of flowers and structural elements and a variety of butterflies and other insects, salamanders, birds, and (yes, alas) deer.

  7. Linda says:

    My smaller than usual garden is horticultural. Married to a United Methodist minister, our current garden is too shady for our sun loving perennials that we move around with us, they are just hanging out until we retire and find a sunnier place (some bloom and some don’t). I haven’t bothered planting a shade garden at this location because the ticks are so awful. This concept intrigues me, because as we both get older, less maintenance will be highly prized.

  8. Carroll Salomon says:

    This interview and book are so exciting to me. I think I’ve “accidentally” created a plant community. Four years ago I deliberately planted sumac as a border on the corner of our property – to create a hedge with leafy shade that would make our side yard more private and shield it from the road and traffic. I hadn’t figured out the under story part, and didn’t really know what I was doing – but the first year I planted vinca and mulched the whole border with 6 inches of wood chips. Every spring, when all the natural wild stuff started coming up, I weeded selectively (dandelions, grass, vetch) and let everything else take its course. Each year it gets more beautiful – and less work!

  9. Anne says:

    Thanks for bringing up the subject of sustainability and maintenance. I think that’s a really important point people should think long and hard about before planting.
    It was also refreshing to hear someone talk about fireworks because that’s exactly how I think when I’m planning & planting…what’s going to go Boom! next.

  10. Sally says:

    Such an exciting thesis. I garden on nearly 4 acres and am always looking for ways to minimize the chores. I strive for self maintaining gardens (ha!) by having a lot of self seeding ornamentals that (to an extent) replace the weeds and then only need to be thinned. My mantra is whatever can grow here can stay here. No matter where the plant originates, if it can live in peace with the others, it is welcome. I appreciate some of the guidelines in the podcast to help me organize plantings in a more eye appealing way. Thanks Margaret for bringing so many interesting ideas to us.

  11. MEW says:

    This approach is how I intuitively set out to garden when I bought my small suburban home. I look at what likes to take over and allow it to do so, adding layers of structure or color or whatever but painting with a broad brush. I have only 1/3 of an acre, but lots of plant communities and some “designed” beds. I allow “weeds” to do their thing too, only pulling out those that tend toward the messy and unkempt later in their season. When I move to a larger property, I hope to figure out how to manage swaths with this idea of layers and structure and everything weaving together. It seems to be a natural outgrowth of Piet Oudolf’s philosophy and I’m glad it’s catching on.

  12. Ginger Smith says:

    My goal has always been to create a sustainable garden. I love working in my garden, but I do not want to babysit it. It is taking some time because I can’t afford to just go out and buy a lot of plants. I believe I am getting to the point where my garden is slowly revealing itself to me and I can see its shape and structure. I have dry shade with very tall oaks, maples and beech trees all around. Planting under and around them is challenging.

  13. Sharon says:

    It just so happens that I have this book on my wish list, because I want to establish beds that are well-layered and natural looking.

  14. Sandy says:

    This is a very intriguing topic and the book sounds like it would be very helpful. I have many areas that would be so great for this type of planting. Margaret, I always enjoy your programs and your website. Thank you.

  15. Karen says:

    My perennial garden is my “management” area I guess you could say. I do very little to it except cut out some plants that have finished blooming and are looking awful or cutting some plants back so they will re bloom. I do need to work on the mulching layer though. I LOVE that idea. My echinacea fall over because there are no grasses to hold them up. Ditto with my rudbeckia and daisies. I have mulch in some areas, but I’d like to do the green mulch thing. Would love to read this book!

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