Designing with Plant Communities

Gardeners, both new and experienced, often ponder how best to design or re-design their gardens, and in today’s “Ask a Master Gardener” (March 25), we learned from Ben at “Wild by Design”, about designed plant communities. This concept aims to reflect the plant communities found in the natural environment when landscaping urban or public places. When designing an ecosystem, rather than considering simply individual plants, the aim is to create spaces that are better for wildlife, seasonally dynamic, and leave less space for weeds.

Getting Started

To create a landscape full of life, including pollinators, Ben considers both the density and diversity of species to be planted. The plantings are designed (see diagram) with a layer of larger plants that create a visual structure, a seasonal theme layer and ground cover layer. 

Credit: Planting in a Post-Wild World © 2015 by Thomas Rainer and Claudia West

Both native and non-native plants can be incorporated into a designed plant community. It is purposefully diverse, mimicking the rich variety of plants in a native meadow or prairie grassland. As many as 20-25 species may grow in a single small raised bed resulting in an ever-changing array of flower blooms over the weeks and months of the growing season.

Numerous examples of plant groupings which bloom throughout the year illustrated Ben’s talk –  the emergence of wildflower Prairie Smoke (Geum triflorum) in April followed by waves of flowering bulbs (tulips, daffodils) in May, Eastern Bee Balm (Monarda bradburiana) and Alliums in June, then Calico Penstemon (Penstemon calycosus) and Butterfly weed (Asclepias tuberosa), and finally a shift to Blazing Star (Liatris aspera) and Brown-eyed Susan (Rudbeckia fulgida var. deamii) in September. Plantings are closely grouped so that weeds are crowded out.

Credit: © Wild by Design 2020. All rights reserved.

Ground cover plantings are an important component of the ecosystem and can be thought of as “green mulch” (no need for commercially purchased mulches!). Suggestions included sedges (Carex sp) or native wild strawberry (Fragaria virginiana or F. vesca), which can tolerate shade later in the season as other plants push up through the ground cover. 

For the Home Garden…

For the home garden, two types of planting for a designed plant community were suggested:

Short mounded plantings are suited to existing gardens where there is a need to work around trees and shrubs that are already in place. For these clumped groupings, no mulch is needed as the plants themselves occupy the space. Just a few of Ben’s suggestions included:

  • Amsonia ‘Blue Ice’ (Blue Star) – grows to 12-18” in width and height, with blue star shaped flowers, and does not spread agressively
  • Allium ‘Millenium’ – compact clump of glossy green foliage with bright purple flowers, much loved by bees
  • Sedum “Matrona’ – also known as stonecrop, this is a sun loving late summer bloomer, with pink flowers on tall stems, also loved by pollinators
  • Coreopsis verticillata ‘Zagreb’ – fine textured foliage with yellow flowers, this blooms from early to late summer
  • Calamintha nepeta subsp nepeta – this is the Perennial Plant Association 2021 plant of the year! It features a cloud of tiny white flowers, with fragrant minty foliage
  • Salvia nemerosa – one of many types of sage, native to dry meadow habitats, featuring purple or lavender spikes

Tall prairie type plantings are another option for home gardeners, with the goal being to grow tall (6-7’) species with leaves that travel all the way up the stem for an attractive full appearance. Again there were many suggestions:

  • Phlox paniculata ‘Jeana’a tall, mildew resistant phlox that’s proven to be highly attractive to butterflies
  • Mondarda fistulosa ‘Claire Grace’ – while native Bee Balm is prone to mildew, this nativar is mildew resistant and more importantly in a Mt. Cuba study appears to be extremely attractive to pollinators
  • Eryngium yuccifolium (Rattlesnake master) together with Panicum virgatum ‘Shenandoah’ (Switchgrass) work well together architecturally
  • Coreopsis tripteris ‘Gold Standard’ – late summer yellow flowers that attract butterflies
  • Calamagrostis ‘Karl Foerster’ – a popular ornamental grass that provides an excellent strong vertical element to this type of planting
  • Eutrochium purpureum (Joe Pye weed), a native species, planted with P. paniculata (tall phlox) does well in a moisture-retentive soil in sun or part shade.

For either type of garden, there are many more options. Watch for Nancy’s upcoming talk where she’ll be sharing a design for a sun loving, native focused plant community. Have fun and experiment to learn what works best in your landscape (and that attracts the most wildlife!) And check out our Meadowscaping page for more ideas.

Growing in Grit

Credit: © Wild by Design 2020. All rights reserved.

Ben also introduced the relatively new concept of using alternative substrates to create a simple to manage and resilient garden, particularly in public spaces. Where resources (maintenance time and money) are scarce, a “gravel garden” utilizing a bed of sterile pea gravel or sand (80%) with weed free compost (20%) at a depth of 10-20 cm, allows plants to establish quickly without being out-competed invading weeds. More information on Ben’s exploration of this type of garden bed, is available here