Using native plants in containers brings a bit of nature to your doorstep. The mini-habitat you create will benefit pollinating insects seeking food and shelter. Native plants are relatively pest-free, they can live for years, and the planting process is no different than that for traditional summer-flowering annuals.
When you plant a container, yours is the role of Mother Nature. Not only do you select the container and choose what to grow, but you also provide the potting mix, the nutrients, and the water. Almost anything can serve as a container, but the most important thing is drainage. If you become enamored of a ceramic or plastic container without drainage, simply drill holes in the bottom. A container 18 to 20 inches across and 20 to 24 inches high will work for three to five herbaceous perennials.
Smaller containers can be used for planting single species. Large containers should be weighted with rocks or other materials to prevent them from blowing over.
Previous Columns
Commercially prepared potting mix — organic, if you prefer, or peat-free, if available — produces the healthiest plants. These mixes are pathogen-free and hold water while draining well — the soil is moistened but not soggy. They often come with nutrients sufficient for the first year. (Check the label.) Many native plants prefer lean soil; be mindful when adding fertilizer. Do not use garden soil; it is too heavy and will not drain properly.
Watering is a critical chore. In summer, your container garden will need at least daily watering, even if it rains. Judge dryness by lifting the pot. Well-watered containers will be heavy. (Planted containers can be difficult to hoist. You might want to invest in a water meter.) Clip dead foliage to keep your plantings looking neat, but leave flower heads to produce seeds for birds. To overwinter, bring your containers into an unheated space where the temperature does not drop below freezing. Or collect them in a sheltered spot and protect them using a tarp, mounded leaves, or hay. After two growing seasons, refresh your container. Lift the plants, root prune and divide as necessary, and replant them using fresh potting mix.
Use the gardener’s trifecta – thriller, spiller, filler – when designing your containers. Thrillers are the tallest, spillers creep or drape over the sides, and fillers, well, fill the middle. When you go plant shopping, keep in mind the light requirements (full sun, part sun, part shade, or shade) and watering needs (some plants like it on the dry side and others are thirsty) of the plants you choose, and group like with like.
Natives do not bloom continuously, so foliage shape and color take center stage. A variety of leaf forms and textures will bring visual interest to your design through the season.
Heuchera, or coral bells, are container workhorses, good for sun or shade. Their heart-shaped leaves set off narrow or frilly foliage, and the many cultivars have leaf colors that can be used to contrast or complement companion plants.
Ferns are beautiful in shade containers, stunning as singletons, or in combination plantings. Ostrich fern (Matteuccia struthiopteris), Pennsylvania sedge (Carex pensylvanica), and coral bells (Heuchera americana) work well together, or plant ‘Lady in Red’ fern (Athyrium filix-femina ‘Lady in Red’) with cardinal flower (Lobelia cardinalis) and Heuchera ‘Plum Pudding.’
Grasses and sedges add texture with their spiky foliage. Try little bluestem (Schizachyrium scoparium) with giant blue hyssop (Agastache foeniculum) and calico aster (Symphyotrichum lateriflorum). Despite the unsettling name, rattlesnake master (Eryngium yuccifolium) is excellent for a large sun container: the bluish yucca-like leaves and interesting round flower heads make a dramatic statement. Combine it with purple coneflower (Echinacea purpurea), threadleaf coreopsis (Coreopsis verticillata) and moss phlox (Phlox subulata). Try your luck at attracting hummingbirds with vivid obedient plant (Physotegia virginiana ‘Vivid’), Heuchera ‘Citronelle’, and old field goldenrod (Solidago nemoralis). Or keep it simple and plant a small water garden. Just one American lotus (Nelumbo lutea) makes for a beautiful container, elegant and tranquil, all summer long.
Although gaining popularity, natives are still a specialty item. Grow Native Massachusetts has a comprehensive list of native plant nurseries on their website, grownativemass.org. Never dig plants up from the wild.
Dorothy gardens in Belmont where she lives with her husband, Steve, and their dog Jasper. She has six grandchildren — all perfect by definition — and has enjoyed introducing them to gardening. She has an abiding interest in nature and is always amazed by the wonders to be found in her own backyard.
