Low-Maintenance Plants for Slopes
Slopes are definitely challenging, garden-wise. Watering and drainage are problematic, not to mention access in general, for plants that need deadheading or any other routine maintenance. Fortunately, I learned in time that there are scads of low-maintenance, drought-tolerant plants that can cover a hillside with attractive foliage and flowers. They also provide the added benefit of preventing soil erosion, which is a very good thing if the hillside is just ten feet from the back of your house (like mine).
Because fall is a great time to plant many perennials, including hardy groundcovers, this is a good time to turn your attention to any troublesome slopes that are on your property. Following are either western native or drought-tolerant, low-growing plants that make light work of routine “gardening” on slopes. Most grow to six to 12 inches tall, but a few can reach 24 inches. Most can take direct sun, but a few look their best with a little afternoon shade. The list is loosely organized by virtue.
No-water wonders These three top my list for low-maintenance plants that are happy on a hot, dry hillside: creeping California lilac (Ceanothus), with smoky purple flowers the bees love; creeping manzanita (Arctostaphylos uva-ursi), with tiny, bell-shaped pink flowers and red fruit; and prostrate rosemary, with pale blue blooms and scented foliage. All three bloom in spring, and once established, require zero supplemental water. The only downside is that these plants are relatively slow growing, so if you want to cover a slope in a hurry, choose from other plants mentioned below.
Fast coverage Native dwarf coyote brush (Baccharis pilularis) is one of the fastest-growing, toughest groundcovers around. Low-growing wall germander (Teucrium chamaedrys) sports small, glossy, dark green leaves and teensy lilac flowers. Creeping St. John’s Wort (Hypericum calycinum) will easily cover a problematic slope, and its fairy-like yellow flowers are lovely; but it can be invasive, so site it with that in mind. St. John’s Wort is one of those hardy groundcovers that looks better if it receives some afternoon shade.
Dazzling flowers Most of the plants mentioned above have lovely blooms, but there is nothing like the car-stopping appeal of a carpet of pink-flowering, creeping thyme. Rockrose (Cistus) is a small, mounding bush that is covered with pink or white crepe-paper-like flowers in spring and summer, and probably wins the prize for a plant that thrives on neglect.
Interesting texture If you like a more rock garden/desert look, there is a mind-boggling selection of succulent Sedums, many of which flower in late summer or fall. “Angelina” and “Dragon’s Blood” are two favorites. Creeping junipers can provide dramatic, almost sculptural texture, as well as being evergreen. Artemesia californica “Canyon Gray” is a low-growing, native sagebrush that has feathery grey foliage and is a nice companion to the pink-flowering rockrose.
There are more options for slopes and hillsides, so don’t give up on them too quickly. Here are some resources for finding more suitable plants: University of California’s “The California Garden Web” at http://cagardenweb.ucanr.edu/ The local chapter of the California Native Plant Society at http://www.sierrafoothillscnps.org/
Rachel Oppedahl is a University of California Cooperative Extension Master Gardener of Tuolumne County.
UCCE Master Gardeners of Tuolumne and Calaveras Counties can answer home gardening questions. Call 209-533-5912 or fill out our easy-to-use problem questionnaire here. Check out our website here. You can also find us on Facebook.