For Engaging Ground Covers, Skip the Typical and Pick a Perennial
Wandering aimlessly through the garden center the other day (an occupational hazard), I came across a section called Ground Covers. The plant benches were full of the usual suspects: vinca, pachysandra, liriope, creeping euonymous and ivy, among others.
Nothing unexpected, nothing terribly interesting, reflecting the common perception that ground covers are merely default plantings intended to fill voids, chosen not for love but for necessity to grow where the lawn won't, under trees and on slopes. Under that doctrine, the actual plant choices typically have been as limited as their utilitarian mission.
Horticulturists, however, have a much broader idea of what constitutes a ground cover, an outlook that begins by rejecting the idea that such plants must be evergreen and less than, say, 18 inches high.
Not all perennials, shrubs or ornamental grasses lend themselves to use as a ground cover, but a lot of them do, and by planting them in bold juxtaposition, you can make landscapes that are soothing and engaging at the same time. This has to be done, however, without forgetting the basic functions of ground covers, which is to grow where other plants won't and thus prevent soil erosion and weeds, and to provide some visual relief from the more exalted specimens in the garden.
By definition, you need relatively large quantities of these plants, and the impatient gardener can spend too much on them as a result. To save costs, buy in the smallest containers available and enrich the soil with compost and other organic goodies. If the plant label says to space the perennials 12 to 15 inches apart, go for the loose end of the range. Mulch lightly to retain moisture and suppress weeds, and water and hand weed as needed. Most perennials reach maturity in three seasons.
David MacKenzie, author of "Perennial Ground Covers," offers three sound rules for their use:
· Use only one or a few select varieties in one area to avoid a clutter of different plant types.
· Match the size of the leaves to the scale of the space.
· Choose plants that get along.