Homeowners in search of hill landscaping ideas face a unique dilemma: flora is aesthetically pleasing but the slope of the hill makes irrigation difficult. Grass can provide excellent ground cover, but mowing a hillside---especially on a steep hill with a 2:1 slope---is difficult. That being said, there are several ideas that make the landscaping of hills a lot easier.
Removing flora on hillsides contributes to landslides and soil creep. Landscape hills with an eye on preserving soil stability through root systems that hold plants in place and also provide a hold on otherwise loose earth. Tree roots in particular add sliding resistance to a hillside that might pose landslide dangers. Note also that smaller plants with deep root systems, which stay largely untouched by human activity and care, offer protection against any soil wearing away. Examples of these kinds of plants---for those in coastal regions--are dwarf coyote bushes (baccharis pilularis) and toyon (heteromeles arbutifolia). For anyone with shady problem areas made worse by acidic soil, Siberian carpet cypress (microbiota decussate), which grows in a soil pH of 5 to 7, may be just right. This is the easiest and least expensive of the hill landscaping ideas, but it also requires a hands-off approach to gardening, which may not suit each homeowner's taste.
Provide a Fire Barrier
A workable compromise is the implementation of an informal planting scheme, where varying species of plants may be randomly planted in groups rather than hedges. When choosing this kind of landscaping for the hilly area of a property, remember to keep plants with similar water needs together. Integrate native plants and fire retardant species into your hill landscaping. Some of these plants include agaves, bearded iris (iris germanica) and deer grass (muhlenbergia capillaria). Avoid pampas grass (cortaderia selloana), chaparral pea shrubs (pickeringia Montana) and the blue gum tree (eucalyptus globulus). These plants and shrubs present actual fire hazards within a hillside landscape.
Work Out Irrigation
Avoid water runoff by irrigating with a soaker hose or drip system. Conventional sprinkler systems deliver too much water in too short a time span to allow for proper soil absorption. Support your irrigation by staggering your plantings, which prevents water from merely rushing down a hill in straight lines. Place mulch around new plants to help keep the soil moist and decrease the amount of irrigation required on your hill. Mulch reduces water runoff and also limits soil splashing until the ground cover develops a sufficiently dense canopy of leaves to undertake this task.