Landscaping slopes and hillsides can be a frustrating problem for gardeners and homeowners. Steep slopes in landscapes pose several problems, including the possibility for damaging soil erosion, mud slides and unstable hillsides that can threaten nearby homes or buildings. Steep slopes also can create drainage issues in the landscape and are nearly impossible to safely mow or maintain, while gentler slopes may be more of nuisance than a safety concern. The scale and gradient of the slope will determine landscaping options.
Re-Grading or Planting Grass
If you have a smaller hill or slope in the middle of a flat lawn area, re-grade the slope to make it flat. Depending on the scale of the sloped area, you can regrade simply by using a shovel. For larger areas, you'll need to use heavier excavating equipment and likely will need to hire professionals to do the job. For slight slopes where erosion isn't an issue, plant the area with sheep fescue, blue fescue, creeping red fescue or buffalograss. These grasses don't need mowing to stay attractive.
On steeper slopes where erosion control is an issue and mowing is dangerous, you'll need to take a different approach. One cost-effective solution to landscape a steeper slope is to plant the area with groundcover plants that require little to no maintenance and at the same time control soil erosion. Choose from a variety of creeping, vigorously-rooting groundcovers, such as low-growing junipers (Juniperous spp.), English ivy (Hedera helix), pachysandras and wintercreepers (Euonymus fortunei). If you prefer a groundcover with some color and flowers, try sage groundcovers (Salvia spp.), creeping thymes, periwinkle (Vinca minor), seaside daisies (Erigeron glaucus), phlox or yarrow (Achillea millefolium). Many groundcover choices exist, but you must select one that's appropriate for your climate and the sunlight exposure the sloped area receives.
Planting Trees and Shrubs
If you have a steep slope or hillside where you have not only soil erosion issues but also hill-stabilization concerns, you'll need to landscape the slope with deeper-rooting trees and shrubs. Consider deep-rooting trees like willow trees (Salix sp.), western red cedars (Thuja plicata), the big-leaf maple (Acer macrophyllum), as well as firs (Abies sp.) and pine trees (Pinus sp.). For areas that need erosion control with limited hillside stabilization, plant shrubs like serviceberry (Amelanchior alnifolia), common snowberry (Symphoricarpos albus) or creeping snowberry (S. mollis), red osier dogwood (Cornus stolonifera), oceanspray (Holodiscus discolor) or coyote brush (Baccharis pilularis).
Tarracing is another viable landscaping option for steeper slopes where erosion control and hillside stabilization are issues. Create step-like terraced beds going up the slope using railroad ties, pavers, concrete, rocks or bricks. Terraced planting beds provide a site for growing a variety of plants, including vegetables and herbs. If you provide walkway access, such as steps, between the terraced beds, maintenance will be easier.