A sloped hillside may offer scenic views, but it also can present some of the biggest landscaping challenges. Slopes are more susceptible to soil erosion and drainage issues, and a steep or uneven hillside can be difficult to navigate — making landscape installation and maintenance more difficult.
It’s important to evaluate your property to find the most effective solutions for creating a beautiful landscape while keeping yourself and your property safe.
WHAT TO CONSIDER
Evaluate your slope: Determine the grade of your hillside, whether it’s slight, medium or steep. This will help you decide what solutions will be most effective. A slight grade may be controlled with rocks, mulch and plants to anchor the soil, while a medium grade may benefit from more stabilization. Steep hillsides will require sturdier measures for controlling erosion, such as a retaining wall or terracing.
Analyze the soil: Soil type will affect how well the slope drains and how much erosion might occur. Sand and silt drain more quickly and are more prone to erosion than clay. Less stable soil may require a sturdier option.
Consider drainage: Make sure there’s adequate drainage to reduce erosion and prevent walls from developing cracks, shifting or collapsing. Water runoff that collects at the bottom of a slope may need to be diverted with a French drain or other drainage system.
Determine access: How easy is it to get around your slope? If doing the work and maintenance yourself, are you able to go up and down the hillside safely?
Consult a professional: For a difficult property or complex renovation, hire a landscape designer, contractor or architect who can evaluate your property and offer professional advice. This is especially crucial if you are adding features like rock walls, retaining walls, waterfalls and berms that require specialized equipment and expertise.
MAKE A PLAN
Draw up a design: Make a rough sketch yourself, or consult a landscape professional for a more elaborate design.
Get inspired: Look for hillside landscaping ideas by searching online or visiting local gardens. Seek out similar properties to find out what worked and what didn’t.
Design for accessibility: Make accessibility a top consideration in the design. The easier it is to get around the hillside, the safer it will be, the easier it will be to maintain and the more time you’ll spend outdoors.
Choose a style: Pick a theme, materials and plants that will harmonize with your home’s exterior. Rough boulders, railroad ties and native plants will complement more natural-looking houses, while cleaner materials and formal plantings will blend with more modern architecture.
Create a destination: Construct a patio, seating area or fire pit where you can take advantage of views of your home or the surrounding landscape. These areas also serve as focal points to draw your eye up and down the slope.
Plan garden beds: Decide what kind of garden areas you’d like to include, whether it’s a mixed border, rock garden, shade border, vegetable plot or water-wise strip.
TYPES OF SLOPE STABILIZATION
Mulch: This is a low-cost solution for a gently sloped yard that helps prevent the loss of topsoil, suppress weeds and retain moisture.
Landscape fabric: Landscape fabric can stabilize a gentle or moderate slope and keep soil from eroding. The disadvantage to landscape fabric is that it will eventually break down. Weeds can grow through the fabric, and it may compact the soil and stunt root development.
Rocks or boulders: Individual rocks or boulders can be arranged along a hillside to help prevent soil erosion. For steeper grades, choose angular boulders that can dig into the soil rather than smooth rocks that are more prone to rolling or washing away.
Soil or wooden berm: This can provide a gentler transition to different levels.
Retaining wall: This is a good solution for a steep slope and may entail cutting away a portion of the hillside and constructing a vertical wall to hold the soil. It can be made from rocks, bricks, cinder blocks, cement, railroad ties or other lumber.
Terracing: A steep hillside can be divided into different levels with a series of retaining walls and flat surfaces in between. The flat areas help control runoff and can be used for planting flowers, seating areas or recreational opportunities.
Stairways and pathways: These will help with stabilization, allow easier access and connect different areas together. Create switchbacks on steeper slopes to make pathways safer to navigate.
PLANT SELECTION
A hillside garden is different to plan for than a flat area. Plant roots will help stabilize a hillside and stem erosion, while foliage provides a canopy that slows water absorption during heavy rains. These can include trees, shrubs, perennials and creeping groundcovers, with some varieties more effective than others.
Here’s what to look for, along with some of the best plants to use. Native varieties have the added benefits of being low maintenance and supporting pollinators and wildlife.
Light conditions: Note how the sun moves over the property throughout the day and in different seasons. Choose plants according to their light needs of full sun, partial sun or shade.
Mix it up: Grow plants of different types, including groundcovers, perennials, trees and shrubs, to create an attractive, layered tapestry.
Siting plants: For more efficient water usage and healthier plants, group varieties together with similar watering needs. Since water runs downhill, place drought-tolerant plants toward the top of a slope, with thirstier varieties toward the bottom.