Gardeners usually have intense childhood memories of plants. We may delve into new stylistic fascinations and botanical infatuations, hut chances are we come hack to these early mental images sooner or later, and reinvent them in our gardens. My memories are of untamed, wild places, especially meadows. Open spaces, broad skies, and veils of grass brushing against my skin—that was heaven.
That's why my garden brims with grasses. Do I have a favorite? Without hesitation, Sporobolus heterolepis, also known as prairie dropseed. This graceful, adaptable prairie native is not common in the wild, yet ranges from Saskatchewan to northern Texas and from Pennsylvania to Colorado. It grows well in USDA Zones 3 to 9, but is still rare in gardens. Thanks to one of the founders of the prairie movement, Neil Diboll, owner of
Prairie Nursery in Westfield, Wisconsin, prairie dropseed has become better known. It is his favorite grass, too.
Prairie dropseed is a bunchgrass, forming a flowing mound of shiny, emeraldgreen, narrow foliage about 15 to 18 inches high and two feet wide. Unlike other tine-textured bunchgrasses like fescues and deschampsias, it is not averse to heat and humidity and is amazingly longlived—15- to 20-year-old plants are the norm. Prairie dropseed also doesn't die out in the center like many other grasses do, so it needs no dividing. In tact, its dense, deep, and fibrous root system makes dividing difficult. Should you attempt it. you'll need heavy armament—a machete or sharp shovel. Neil suggests taking large chunks at least two inches in diameter because the grass is slow to reestablish. Typically, a young plant or division takes four to five years to reach maturity. Do cut it back hard early each spring before growth resumes, or if you are allowed, burn it. Burning stimulates tremendous bloom and seed production.
Prairie dropseed insists on at least six full hours of sun, and prefers an entire day. In the moister half of the continent it is considered very drought tolerant; in the interior West and California, the plant needs additional water during the growing season. In nature, it is often found on dry upland soils; in the garden it tolerates both clay and sand, so long as the soil is well drained. Why such an adaptable plant is so rare in nature may have to do with the seeds being short-lived—a year or less—and highly palatable. (The plant itself is not; deer consider it only on last resort.) Should you wish to seed an area, sow in the fall. If spring sowing is more practical, give the seeds two months of dry stratification in an airtight container in the refrigerator, then sow them early, no later than May 15 in the upper Midwest, because prairie dropseed is a cool-season germinator.
The plant itself is intermediate between a warm-season and cool-season grass. greening up in mid-spring, and heading into dormancy by early fall. In midsummer, it sends up three-foot-high, diaphanous flowers that carry on into September. The loose panicles emit a warm, strong fragrance that reminds me of Juicyfruit gum. In autumn, the soft hummocks turn a glowing gold or apricot color. Individuals with red fall foliage are being propagated, as are forms with silvery flowers, arching flower stems, compact growth habit, and red stem color.
Prairie dropseed works equally well as part of a grass matrix that also includes little bluestem, sideoats grama, and prairie wildflowers, as it does rubbing shoulders with the groomed tenants of the most carefully orchestrated herbaceous border. In my garden, prairie dropseed mingles with wild plants of cosmopolitan provenance—Eurasian species tulips, poppies, alliums. South African diascias, dieramas. kniphofias, western American columbines, lupines, and penstemons. Vignettes of my meadow memories are realized right outside the door.