Designed plant communities mimic nature in a visual appealing way
In a recent post, I mentioned Sara Stein's book, Noah's Garden. In it, Stein introduces the concept of "unbecoming a gardener," or relinquishing our need to bring complete order and tidiness to our home landscapes in favor of letting nature shine through more clearly.
The concept of designed plant communities expands upon Stein's idea. Thomas Rainer and Claudia West popularized this approach in their book, Planting in a Post-Wild World: Designing Plant Communities for Resilient Landscapes. Plenty of other garden designers have also embraced naturalized plantings as a way to creatively design landscapes in a more ecologically friendly way.
In essence, a designed plant community uses wild plant communities as inspiration for an aesthetically pleasing garden bed, meadow, or other human-created landscape. Its fundamental characteristics include a high density of plants at several height levels; an aesthetic structure; and compatibly planted species that are able to grow together well.
How designed plant communities differ from traditional gardens
Formal garden beds are often planted in blocks of color to highlight certain flowering plants.
In a traditional garden bed, there may be several to a few dozen plant species positioned to maximize viewing of flowers or foliage textures. Quantities of a certain plant may be grouped together to form a block. Usually, we put plants into our gardens based upon how they look, smell, or feel. We don't think too much about how they act, what their native habitat is like, or how they interact with other plants. We just find plants we like, or create color combinations that work well together. Then we fill space, but often leave room between plants, where we place mulch to suppress weeds. We give room for air circulation, or to keep neighboring plants from competing with one another.
Those of us who are not trained garden designers struggle with how to fit our favorite plants together. My tendency is to research plants to find something I like, and then buy one or two, with only vague ideas about where I'll put them. I'll think, "oh, this is a fragrant plant - better put it close to a door or window," or "this might look nice next to that tall thing in the middle of the bed." The result is a bit of a hodge-podge from a design perspective:
A colorful garden bed, where the plants do not interact very much.
Others who know more about garden design, of course, bring more skill to the process, and can think about things like seasonality, texture, foliage color, and overall bed structure.
However, there is still usually a focus on individual plant species in traditional gardens. We often have to keep the needs of each species in mind. For instance, we'll know that every week, X plant needs deadheading, or Y plant should be watered because it has been dry lately, or Z plant must be fertilized early in the growing season to generate large blooms.
In a designed plant community, by contrast, an area is planted with numerous species, including graminoids (grasses or grass-like plants), forbs (leafy plants), and sometimes shrubs or trees. A ground cover layer or matrix underlies the entire area, with highlighted species either mixed in or set in drifts for visual impact. Taller structural plants punctuate the area to create visual interest. A designed plant community could be an intentional meadow planting, a savannah-like area with grasses and trees, or a woodland planting with ground level, understory, and canopy plants. It is not cared for at the plant level, but rather managed overall by species or through judicious editing.
Natives vs. exotics in designed plant communities
Many plant designers who create designed plant communities support the use of native plants. In fact, they will often research a site to find out what typical wild plant communities look like; what species grow together there; and study how they interact. However, a designed plant community is not necessarily made up of solely native plants. The key factor in designed plant communities is the interaction of the ingredient plants, more than where they originate.
Depending upon your goals, you might want a designed planting to be 100% native, such as the gardens at Mt. Cuba Center in Hockessin, Delaware.
A woodland plant community. Iris, ferns, and geraniums catch the dappled light beneath the forest canopy. A window into the nearby meadow links the spaces together naturally.
Such native plantings contribute excellent biodiversity to closely mimic the ecology of the region. Plants are positioned for maximum viewing pleasure and are interlocked with one another to completely cover the ground. Species with different shapes and growing habits complement each other while providing visual interest throughout the seasons.
Texture and architecture
In a designed plant community, texture and architecture can be the defining feature, as opposed to color in a traditional garden situation. Texture refers to the plants' shapes, leaf design, and movement. Architecture refers to the three-dimensional structure of the planting. For example, a clump of towering Joe pye-weed swaying a couple of feet above a field of grass makes an architectural statement. Once the plants have finished flowering, the seedheads and plant stalks remain and add a structural element to draw the eye.
In the photo above, sedge flops in a pleasing way to create the sensation of waves in the foreground. The plants with rounded leaves behind the sedges convey a completely different, yet harmonious texture at the same height level, while taller shrubs punctuate the back of the planting.
Both texture and architecture allow a designed plant community to offer beauty and interest throughout the year, not only during the growing season. Whereas we often think of "putting the garden to bed" for the winter, a designed plant community is designed to function in all seasons. Plants cover the ground so little to no mulch is required. This prevents soil erosion, slows runoff, and protects plants from winter damage. Seedheads left on stalks offer food to birds, and standing vegetation harbors overwintering insects and small mammals.
Designing for wildlife
Well designed plant communities draw a broad range of wildlife, particularly birds and pollinators. With a focus on biodiversity and visually appealing flowering plants, designed plant communities can be powerful ecological spaces. The dense plant cover provides food, shelter, and nesting space. Many native plant species act as host plants for butterflies and moths. This ecological partnership is the foundation of the food web - more on this in my article on 10 great reasons to add native plants to your landscape.
Meanwhile, underground, the plants' various root systems complement each other. Big clumping grasses and some perennials send their roots down 10-15 feet, drilling through compacted soil and drawing up water and nutrients to the surface. Smaller plants with shallower roots hold the surface soil together. If the plants chosen are well-suited to the site, they won't require fertilizer, mulch, or added water. The soil is naturally maintained and rejuvenated through photosynthesis and decay. Soil organisms will find plenty of opportunities to multiply, thus drawing ground-dwelling insects and their predators.
Choosing the right plants
To create an effective designed plant community, one must learn about different kinds of plants and something about their habits. All plants chosen must be relatively well-behaved, and generally not move around too much. Some movement is inevitable, however, as in nature.
First, consider the planting area. Will it be an open grassland/meadow? Or a woodland glade? A sunny wet area? An exposed, rocky site? Next, find a set of plants that can take those conditions. Include grasses or other grass-like plants in the mix, especially the clumping species (as opposed to the spreading species).
Rainer and West recommend thinking of your planting as having three distinct design layers:
a structural layer containing a few tall clumps or single plants, placed at visually appropriate points (about 1-10% of the plants);a seasonal interest layer, with somewhat shorter plants that bloom colorfully at various times of year, set in clumps, drifts, or dotted throughout (30-40% of the plants); anda groundcover layer, containing plants that will sprawl over any open space beneath the stems and leaves of the taller plants (30-40% of the plants). Think of this as the "plant mulch."
Finally, another 5-10% should be made up of dynamic filler plants, which grow quickly and add a visual pop of color. These may not be long-lived species. In fact, annuals or biennials are fine. Short-lived but readily self-sowing perennials also fit the bill.
Meanwhile, within each layer, grasses or their ilk can account for a significant portion of the plant mix. They provide a foundational texture and fill in space between broadleaf species, especially when the broadleaf plants die back.
One easy way to create a design is to make a base drawing, and then use three separate sheets of tracing paper to depict each layer. You can play around with drifts of seasonal interest plants while maintaining the position of the architectural plants, or vice-versa. The groundcover layer can be uniform or broken into swaths to complement the rest of the planting. Dynamic fillers can be denoted once you have settled on the other layers.
Site prep, planting, and maintenance
As with any planting effort, site preparation is an important first step. The area must be cleared of weeds, either chemically or mechanically. This could take one to two growing seasons depending on the weed situation. So it's not a quick process. The good news is that once you are ready to plant, you shouldn't need to add much in the way of soil amendments. Instead, the plants chosen for the design should be well-suited to the existing conditions. This leads to a lower-maintenance, higher performing plant community.
When laying out the planting, it can help to set out and plant the largest plants first (largest being the architectural plants, not necessarily the largest pots). Then move on to the seasonal interest plants, and fill in with groundcovers. Finally, sprinkle the dynamic filler plants anywhere there is open space left.
Mulch lightly at planting if necessary, and water everything in.
The first growing season will require more attention than following years, because weeds still have a chance to compete with the designed plants. After that, maintenance might entail occasional weeding, plant replacement if necessary, and possibly annual mowing or burning. Large plants could require occasional pruning. Overall, however, the goal is for a lighter management burden compared to a traditional garden.
For more information on designed plant communities
The following books provide much more detailed information on the principles and practices of designed plant communities:
Planting in a Post-Wild World: Designing Plant Communities for Resilient Landscapes, by Thomas Rainer and Claudia West. This book details the ideas and concepts behind designed plant communities, and includes helpful design guidelines to help the beginner think about how to create a planting.
Planting: A New Perspective, by Noel Kingsbury and Piet Oudolf. Kingsbury and Oudolf's text is full of gorgeous photos to demonstrate various planting techniques and plant combinations. At the back of the book they include helpful appendices listing numerous plant species and their growing characteristics.
The Living Landscape: Designing for Beauty and Biodiversity in the Home Garden, by Rick Darke and Doug Tallamy. This book is specifically targeted toward homeowners who want to design their landscapes with nature in mind. The book includes excellent reference charts with various plants' growth habits and ecological functions. It too is full of gorgeous and inspiring photos.