Container Gardening with Native Keystone Plants
Eastern Tiger Swallowtail nectars on Black Eyed Susans and Obedient Plant. Photo by E. L. McCoy
Container gardening is a great way to garden if you have limited space. Have you ever considered growing native plants in your containers? And what might be even better than this, you ask? Why container gardening with native keystone perennials, of course!
Why Keystone Plants?
Keystone plants are the “powerhouses” of native plants. While all native plants are beneficial, keystone plants are the linchpins for entire ecosystems, providing crucial resources for the greatest number of insect species. These keystone plants serve as host plants for insect larvae and also support native bees and other pollinators with their flowers. As the noted scientist and professor emeritus at Harvard University, Edward O. Wilson so eloquently stated, insects are, “the little things that run the world” and without them, most living things on earth would perish very quickly.”
Planting natives is fundamental to responsible gardening and fostering biodiversity. According to Dr. Doug Tallamy, who pioneered the idea of the Homegrown National Park, planting even one keystone plant will help restore biodiversity in your garden. These plants are beautiful, and add interest to your garden. They attract butterflies, native bees, birds, and other insects. We all want a beautiful garden!
Coreopsis blooms in mid-spring to early summer. Photo by E. L. McCoy
These ‘enthusiastic’ keystone native plants produce a copious amount of seed from each flower, which attracts goldfinches and other birds, and they seed themselves around freely. Their large size and tendency to spread through their roots and rhizomes make them an economical choice for covering large areas in the garden.
Using these plants for container gardening checks the box for those who may have physical and space limitations that make large-scale gardening projects unrealistic. Another great thing about native plants is that they are generally very healthy and will rarely be grazed by deer or rabbits. Most of these are drought-tolerant. They won’t need much if any, extra water or fertilizer.
Coreopsis Photo by E. L. McCoy
Choose the Right Native Plant for the Right Native Place
If you are thinking about starting a native plant container garden, there are a few things you need to know. Homegrown National Park, an organization whose mission is to regenerate biodiversity and ecosystem function with the goal of promoting 20 million acres of native plantings across the United States, recommends choosing keystone plants based on your own ecoregion.
They recommend using ecoregions to ensure the plants you choose are suited to your specific region, whether it is a plant for your garden or a plant for a container. According to their website, “We use ecoregions to make it easy to identify the native plants that will work best for your location’s growing conditions and climate.” Williamsburg is located in the Eastern Temperate Forest ecoregion.
Goldenrod supports many native bees. Photo by E. L. McCoy
“This is a different approach from using a state’s native plant listing. An ecoregion is an area that shares common ecosystem characteristics such as weather, seasons, wildlife, and soil and usually includes parts of multiple states. Since states will often have vastly different habitat types and species from one side to the other, ecoregions are particularly useful for geographically grouping native keystone plants.”
“In some cases, the plants for your ecoregion may not line up with your state’s listing of native plants but will perform as a keystone plant.” From Homegrown National Park “Container Gardening With Keystones”
Blue Wood Asters bloom from late summer into fall. Photo by E. L. McCoy
Things to Consider
By now you are probably conjuring up a plan for your own native keystone container garden, but consider a few ground rules before you get started. Just because container gardening can be easier in many respects than traditional yard plantings, there are a few considerations for using these natives in your plantings:
- Use large pots to accommodate extensive root systems these natives need to thrive. Half barrels or 30″ pots may be required for some of these selections.
- Plan to support the largest keystone native perennials, which can grow to over 7′ tall. Place your container near a fence or wall, or provide a trellis. Expect these plants to get larger each year, and consider dividing them in early spring if they are growing too large for their pot. Divisions can fill new pots or can be shared with friends.
- These perennials need to remain outside during the winter, but clay pots may crack in freezing weather. Consider using composite, plastic, wood, or especially fired clay pots which will survive cold winter weather.
- A large percentage of the seed produced by keystone natives will germinate. Deadhead spent flowers if you don’t want a colony to develop around your pot.
- These perennials bloom for about six to eight weeks. Consider mixing longer-blooming plants in the same pot to extend the season of interest for your planting.
- Avoid using any pesticides or herbicides on plantings for wildlife.
Cutleaf Coneflower blooms in late summer and early fall. It may grow to 10′ tall. Photo by E. L. McCoy
Keystone Native Plants for the Eastern Temperate Forest Ecoregion
Coreopsis lanceolata Lanceleaf Coreopsis Full sun to part shade, Zones 4a-9b, to 3’ tall, Blooms May -July
Euthamia caroliniana Grass Leaved Goldenrod Full sun to part shade, Zones 5a-10b, to 6’ tall, Fall bloomer
Gaillardia pulchella Blanket Flower Full sun to part shade, Zones 4a-9b, to 2’ tall, Summer bloomer
Helianthus divaricatus Woodland Sunflower Partial Shade, 3a-9b to 7’ tall, in late Summer bloomer
Oenothera biennis Evening Primrose (biennial) Full sun to part shade, Zones 4a-8b, to 5’ tall, Summer bloomer
Rudbeckia fulgida Orange Coneflower Full sun, Zones 3a-9b, to 3’ tall, Blooms August – October
Rudbeckia hirta Black Eyed Susan Full sun to part shade, Zones 3a-8b, to 4’ tall, Blooms June – September
Rudbeckia laciniata Cutleaf Coneflower Full sun to part shade, Zones 3a-9b, to 10’ tall, Blooms July-October
Solidago caesia Wreath Goldenrod Full sun to part shade, Zones 4a-8b, to 3’ tall, Blooms August -October
Solidago rugosa Wrinkleleaf Goldenrod Full sun to part shade, Zones 4a-8b, to 5’ tall, Blooms August -October
Symphyotrichum cordifolium Blue Wood Aster Full sun to part shade, Zones 3a-8b, to 4’ tall, Fall bloomer
Symphyotrichum leave Smooth Aster Full sun to part shade, Zones 4a-8b, to 4’ tall, Fall bloomer
Goldenrod blooms from late summer through the fall at the Williamsburg Botanical Garden. Photo by E. L. McCoy
You can log your native keystone container gardens on the Homegrown National Park map on the website. You may take comfort in knowing that you are doing your part to support our fragile ecosystems and, as they say, “every square foot counts!”
Resources:
Wilson, Edward O. “The Little Things That Run the World (The Importance and Conservation of Invertebrates).” Conservation Biology. Vol. 1, No. 4. (Dec. 1987) pp. 344-346.
Mellichamp, Larry. Native Plants of the Southeast: A Comprehensive Guide to the Best 460 Species for the Garden. 2014.
Oudolf, Piet and Henk Gerritsen. Planting the Natural Garden. 2019.
Tallamy, Douglas. Nature’s Best Hope: A New Approach to Conservation That Starts in Your Yard. 2020.
Vogt, Benjamin. A New Garden Ethic: Cultivating Defiant Compassion for an Uncertain Future. 2017.
McCoy, Elizabeth. “Invitation to a ‘Homegrown National Park‘.” Jccwmg.org website. 2022.
Tallamy, Douglas. “Container Gardening with Keystones.” Homegrown National Park.org website. 2023