By Deb Courtner, Colorado Master GardenerSM, Colorado State University Cooperative Extension, Denver CountyDrought conditions and water rationing have left lawns throughout the metro area dotted with bare spots. These patches are not only weed magnets, but if large enough, they can cause soil erosion.
Despite relaxed watering restrictions, most of us still can't irrigate as often as we'd need to in order to establish sod, so it's time to look at other options. And drought-tolerant ground covers are among the best at adding color and texture, as well as reducing erosion.
They also can make your life easier. "Ground covers require less maintenance than turf overall because you don't have to mow them," says Carl Wilson, Colorado State University Cooperative Extension horticulturist in Denver. "But, you still have to weed them. And with some, you have to keep them in bounds with pruning."
The key consideration is to use the appropriate plant for a given situation, Wilson says. "Turf is the best plant for controlling soil erosion, followed by ground covers, then mulch," he explains. "Turf also tolerates foot traffic. So ground covers aren't a replacement for turf in many areas."
But when the growing gets tough for turf, ground covers offer an alternative for covering bare spots and slopes.
Homeowners can easily transplant these newcomers later once it becomes practical to grow new grass. Then again, homeowners may like the plants so well that, over time, they may replace larger areas of their lawn with ground covers.
Popular sun-loving perennials include:
Turkish speedwell (Veronica liwanensis). This fast-spreading beauty with round, glossy leaves is eye-catching even when not in bloom. But each spring, delicate periwinkle blue flowers form a dense carpet of color. "Turkish veronica is very adaptable to poor soils," Wilson says. This 1997 Plant Select winner grows about 2 inches tall and 18 inches wide.
Sun rose (Heliathemum nummularium). This short, bushy evergreen is a spring bloomer whose flowers resemble miniature fried eggs on threadlike stalks. The flowers have raised yellow centers surrounded by flat petals of white, pink, raspberry or red, depending on the variety chosen. This perennial will grow 4 to 6 inches tall and 15 to 18 inches wide.
White-flowered poppy mallow (Callihroe alceoides "Logan Calhoun"). Like its popular burgundy cousin (Callihroe involucrata), white-flowered poppy mallow is a showstopper when it cascades down a west- or south-facing slope.
Its goblet-shaped flowers, surrounded by deep-cut leaves, appear continuously from June through September. This versatile plant can be trained to climb fences or trellises, or can simply be planted in beds to meander gently among shrubs. It will grow 6 inches tall, and its trailing stems will reach 28 inches.
Greek yarrow (Achillea ageratifolia). Unlike its taller yarrow cousins, Greek yarrow produces a low-growing, dense evergreen mat. It blooms profusely in late spring with clusters of small brilliant white flowers with yellow-white centers. A slow-spreading perennial, it eventually will grow 4 inches tall and 18 inches wide.
Woolly thyme (Thymus pseudolanuginosus). Gardeners appreciate this ground cover for its soft gray-green mat rather than for its tiny, sporadic blooms. Because it tolerates moderate traffic, homeowners frequently use it between walkway pavers. This fast-spreading plant grows 1-2 inches tall and 18 inches wide.
Hardy yellow iceplant (Delosperma nubigenum). This eye-catching succulent boasts plump lime green leaves that turn reddish-purple in fall and winter. A late spring bloomer, it produces dazzling, fluorescent-yellow daisy-shaped flowers. The perennial tolerates hot sun and pavement heat but requires well-drained soil. A fast spreader, it grows 1-3 inches tall and 12 to 16 inches wide.
If you decide to replace turf areas with ground covers, Wilson recommends killing the turf with glyphosate (contained in Roundup and other brands). "Once the grass dies, the homeowner can dig through the grassy mulch and plant the ground covers," he explains. The grassy mulch will hold the soil in place, especially on slopes, while the ground covers get established. For more information, see Factsheet 7.234, "Xeriscaping: retrofit your yard."
Photos: Judy Sedbrook
© CSU/Denver County Extension Master Gardener 2010
888 E. Iliff Avenue, Denver, CO 80210
Date last revised: 01/05/2010