Cover Steep Sites with Ground Covers

Maintaining lawn grass on a sloping site is a real headache. It’s hard to decide which is worse: hauling the mower up and down a steep grade, or trying to stand sideways on a slope to swing a string trimmer over the grass. Plus, there’s the fact that tasks like watering and feeding grass growing on slopes are just more difficult than grass grown on the flat.

Why not end the headaches altogether and replace lawn grass growing on some of your tougher sites with tough, drought tolerant ground covers that will really thrive on sunny slopes?

Landscaping Tips for Slopes in Full Sun

Shrubs for Sunny Slopes

• Creeping juniper (Juniperus horizontalis). This North American evergreen ranges from 1 to 2 feet tall and spreads to 8 feet. For truly ground-hugging plants, look for cultivars such as 10-inch-tall ‘Blue Chip’, 12-inch ‘Bar Harbor’, or 7-inch ‘Emerald Spreader.’ ‘Wiltoni’, also sold as ‘Blue Rug’, is a fast-growing cultivar that reaches 4 to 6 inches in height. Junipers tolerate heat, drought, salt spray, and heavy clay. Zones 3 to 9.
• Dwarf forsythia (Forsythia ‘Arnold Dwarf’). While most forsythias reach 8 to 10 feet in height, ‘Arnold Dwarf’ is a handsome 2- to 4-foot-tall selection perfect for covering ground. Plants spread to 6 or 7 feet at maturity and tolerate partial shade, although they will not bloom as well. They bear bright yellow flowers in spring. Zones 5 to 8.
• Fragrant sumac (Rhus aromatica) ‘Gro-low’. Also called lemon and sweet-scented sumac, ‘Gro-low’ is a dwarf cultivar of a native shrub that spreads aggressively by suckers and is perfect for covering tough slopes. Plants have deeply cut leaves with leaflets arranged in a featherlike fashion. They bear tiny yellow flowers in spring. Fall color is spectacular and ranges from orange to red-purple. Zones 3 to 9.
• Creeping St. John’s wort (Hypericum calycinum). Also called Aaron’s beard, this species spreads vigorously by underground runners. Plants feature rounded, dark green leaves and golden yellow, 3- to 4-inch wide flowers from midsummer to fall. Foliage is evergreen to semi evergreen, and plants may be killed to the ground north of Zone 6. Provide afternoon shade from about Zone 8 south. Zones 5 to 10.

Check out these 9 drought tolerant shrubs for more inspiration on your slope

Perennials for Sunny Slopes

• Daylilies (Hemerocallis spp.). Ranging from 1 to 3 or more feet tall, daylilies bear trumpet-shaped blooms in shades of yellow, orange, red, maroon, and cream. Many flowers are bi-colored. All daylilies are tough plants with fleshy roots that help them withstand drought, although tough conditions reduce bloom and rich, well-drained soil is best for flower display. Plant broad drifts of daylilies across a slope, and intersperse them with ground covering shrubs or other perennials. Zones 3 to 9.
• Hardy ice plant (Delosperma spp.). Tolerating both heat and drought, hardy ice plants bear succulent leaves on sprawling, 2 to 6 inches tall stems. Plants bear bright, daisylike flowers in summer. Use them for filling in around boulders or covering ground around larger shrubs. They require well-drained soil. Many species are suitable for hot climates, but D. nubigenum, with orange-red flowers, is hardy in Zones 5 to 10. D. cooperi, with magenta flowers, is hardy in Zones 7 to 10.
• Snow-in-summer (Cerastium tomentosum). This old-fashioned perennial is evergreen, with silver woolly leaves. Plants spread indefinitely and range from 6 to 12 inches in height. They bear clusters of small, starry white flowers from late spring into summer and tolerate any well-drained soil, including pure sand. Plants spread fastest in areas with cool summers. In Zone 7, give them light shade to prevent the centers of the clumps from dying out in hot, humid weather. Zones 3 to 7.
• Orange coneflowers (Rudbeckia fulgida var. sullivantii ‘Goldsturm’). These tough, 2- to 2½-foot perennials produce dark-centered, orange-yellow daisy-type flowers from midsummer to mid fall. Plants spread by rhizomes to form broad drifts. While happiest in rich, well-drained soil, they tolerate drought. Combine them with ornamental grasses and sedums such as ‘Autumn Joy’ to cover a slope with fall color. Zones 3 to 9.

Want more tips for planting on slopes? Check out this post

Secrets to Planting Slopes Successfully

Rainwater runs down slopes quickly, leaving little time for it to soak into the soil. So, slowing down runoff is the secret to success when planting ground covers on a slope. To give water time to sink into the soil, try to provide a level planting area around each plant. Ideally, the planting sites should be cut back into the slope and slightly dish-shaped so that water collects and sinks into the soil. You can also install a short board in front of each plant to help hold the soil and slow runoff. (Remove these once plants are established or let them rot in place.) Be sure to stagger the rows of plants, to help prevent water from creating deep gullies on its way down the slope.

For more tips on controlling soil erosion, check out this post

Another excellent option is to place soaker hoses across the slope so you can water easily until plants are well established. After planting, be sure to mulch each plant to help keep the soil moist.

Covering a slope with ground covers can make a huge difference in the amount of time it takes to keep your yard looking its best. There are many other options for using ground covers to reduce maintenance.