A sloping landscape presents unique challenges. Water running downhill causes erosion, carrying away topsoil. However, with a bit of planning and the correct plant selection to halt erosion, a steep bank can be an attractive plant that is the envy of the neighborhood.
Is your slope shaded or sunny, on the edge of a wooded area or in an open meadow? To plan your erosion-control landscaping project, evaluate the slope of the hill, how much sunshine it receives daily and the way water works its way down the hill. Make a sketch of the hillside and try to picture how it will look when planted and mature.
Shrubs for slopes
Low-maintenance shrubs are useful tools in controlling slope erosion. Shrubs such as Cotoneaster, sea berry, sea buckhorn, holly or juniper are hardy, disease resistant and drought resistant. A visit to your local plant nursery will help you locate plant varieties that thrive in your United States Plant Hardiness Zone. In cold climates with heavy snow accumulation, shrubs planted on a hillside in staggered rows serve as a snow fence or windbreak. Berry-bearing shrubs add spring flowers, food for wildlife, colorful fall foliage and winter interest.
Anchor soil in place with trees
Small conifers anchor soil with a network of roots, adding vertical interest and greenery to a previous barren hillside. Blue juniper is an excellent choice that reaches a mature height of 15 to 20 feet. If the hillside has a tendency to stay damp, willow or red maple, which thrive in U.S. Plant Hardiness Zones 3 through 9, are other good choices for slope planting. Plant shallow rooted, shade loving plants such as impatient and hostas under trees.
Build a rock garden
Faced with a steep hill that is too hard to mow? Turn a brown and barren hillside into a delightful rock garden. Enlist the services of a landscape contractor with the correct earth moving equipment to terrace the hill to allow pathways and to position boulders to control water flow. Stagger clusters of rocks in partially buried grouping to prevent water from running straight down the slope.
Once the hill is terraced, enrich the soil with a thick application of equal parts of peat moss and age herbivore manure (cow, sheep, horse, goat, llama) and work into the soil. Plant the slope with hardy day lilies, wooly thyme, lavender, bulbs and perennials to create an eye-catching splash of color. Fill in open gaps with smaller stones and groundcover plants suitable to your growing area. Fragrant herbs are easy to grow in the rock garden, providing a cutting garden for culinary and decorative use. Coreopsis, marigolds and golden rod will add a splash of brilliant color.
Incorporate native plants into the rock garden such as mosses, plantain lilies and ferns to offer evergreen accents. Fill in open spots with plantings of chokecherry, Saltbush, bayberry, Arrowwood, mountain laurel, spreading Japanese Jew and native ground covers. Contact your local county extension office to determine which native plants are best suited to your growing environment.