November 11, 2017
A ground cover, literally, is something that covers and protects the soil. While this may include bark, wood chips and traditional lawns, there are many reasons to choose from a wide variety of low-growing plants that are easy to maintain and environmentally friendly.
Ideal ground covers are hardy and easy-care, with a dense and spreading habit. They may be annuals, perennials, grasses, woody shrubs or vines, ranging in height from an inch or less to several feet. They are available in many textures and colors and, when properly selected for growing conditions, require little effort and last for many years.
Uses range from highly practical to aesthetic. Ground covers can be a solution for problem areas where little else will grow, such as steep slopes, spots with poor soil and places where rocks, boulders or tree roots make cultivation and upkeep difficult.
Most of us are aware of the benefits of replacing thirsty lawns with plants that require less water, fertilizer and maintenance. Ground covers also control weeds, protect soil from extreme temperatures, and provide habitat for wildlife and beneficial insects. On slopes, they reduce runoff and help prevent erosion.
Aesthetically, ground covers can provide a restful expanse of green or splashes of vivid color. They may be used to soften edges and borders, unify groups of plantings, or around stepping stones to create a pathway.
When planning a low-maintenance ground cover, the secret to success — as always — is to know your site and make selections that will thrive there. Consider your climate zone, soil type, sun exposure, and water and drainage requirements. Natives are particularly appropriate, since they are adapted to our climate and resistant to many pests and diseases.
Avoid plants that will outgrow your space, and place them far enough apart to accommodate their mature size. Large areas lend themselves to taller, larger choices and to a combination of species, either in drifts or intermingled.
Even low-maintenance plants need occasional care. Some ground covers benefit from periodic pruning or shearing to keep them looking their best. And even those that are drought-tolerant require some irrigation, especially in warm inland areas.
In addition to lawn replacement, which has been covered extensively, here are some other uses for ground covers and a few suggestions for Marin climates.
For hillsides where soil may be poor or rocky (the last four are best for erosion control. All but ceanothus are deer-resistant):
• Arctostaphylos (Manzanita): Two choices are ‘Emerald Carpet’ (sun) and ‘Carmel Sur’ (part shade inland).
• Baccharis pilularis ‘Pigeon Point’ (Dwarf coyote brush): Sun.
• Ceanothus griseus horizontalis ‘Yankee Point’ (California lilac): Blue flowers in spring. Afternoon shade inland.
• Rosemarinus officinalis ‘Huntington Carpet’ (Rosemary): Deep blue flowers in spring. Sun.
For long-season color with low to moderate water:
• Ceratostigma plumaginoides (Dwarf plumbago): Brilliant blue flowers. Sun to part shade.
• Convolvulus sabatuis (Ground morning glory): Lavender. Sun to part shade.
• Geranium spp. (Cranesbill): Many varieties and colors. Sun to part shade.
• Lantana spp.: Lavender, yellows, pinks and oranges. Sun.
• Nepeta spp. (Catmint): Flowers in white, lavender, blue and yellow. Sun.
• Verbena spp. Pinks and purples. Sun.
For small spaces and around hardscape:
• Ajuga reptans (Carpet bugle): Partial shade and regular water.
• Dymondia margaretae (Silver carpet): Grey-green foliage, yellow flowers. Sun.
• Pratia pedunculata (Blue star creeper): Sun to part shade.
• Sedums spp. (Stonecrop): Sun.
• Thymus spp. (Thyme): Elfin or woolly varieties for hardiness and color. Sun.
For many more ideas, some excellent resources are available in local libraries:
• “Plants and Landscapes for Summer-Dry Climates,” East Bay Municipal Utility District (2004)
• “New Sunset Western Garden Book,” Sunset Publishing (2012)
• “Western Garden Book of Easy-Care Plantings,” Sunset Publishing (2015)