Landscaping Steep Slopes | Challenges & Solutions

Landscaping steep slopes can be a challenge. Your house

may be at a higher elevation with your land sloping down and away from it.

In another situation, your land may be sloping towards your house, your house being at a low point. When landscaping steep slopes in this situation, proper drainage is particularly important.

Regardless, landscaping steep slopes takes some creativity and knowledge to design for both nice aesthetics and function.

The extent of the challenge depends on actually how steep of a slope we are talking about. Sometimes a planting design alone will work, while in other situations terracing would be best.

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Landscape Grading - Visuals For Landscaping Slopes

• The steepest slope that you can mow comfortably is 3:1 or thirty three percent. Imagine being able to mow on a hill that is the steepest you can go. That's a 3:1 slope. Technically, this means that there would be a one foot rise in elevation for every three feet of distance. In other words, if you had a slope that was nine feet long, the top of the hill would be three feet higher than the bottom.
• Most of you have seen handicap ramps. A handicap ramp slopes at a maximum of eight percent, and this is usually the case.
• A patio will slope at two percent, therefore pretty level. Some contractors might reduce this amount slightly, but I feel more comfortable with the two percent. A patio is designed this way so that water travels away from the house.

Hillside Landscaping

The maximum slope for hillside landscaping should be 3:1.These types of areas can be dry due to water travelling downwards and not seeping into the ground. Therefore, use plants that are somewhat drought tolerant. Watering can be a problem with steep slope gardening. A sprinkler system helps tremendously, particularly if it is a large sloped area.

In addition, if it is a large area there is also the problem of access for weeding. Adding a thick layer of mulch, three inches deep, will help. There are also chemicals available to deter weed growth. However, there are more environmentally friendly solutions.

For example, having the complete area covered by plant material will keep most weeds from emerging. Using masses of groundcovers, especially the faster growing or aggressive ones, is an excellent option. Planting groundcover when landscaping steep slopes should be a large part of your landscape design, which can include shrubs, perennials, and even some landscape trees to create shade.

Use masses of plant types when landscaping steep slopes (and in all landscape design). Keep the taller ones at the top with the lower plants towards the bottom. However, do break this "rule" to avoid monotony.

For example, you might use a group of five to seven Weigela for the taller plants and then a group of two to three foot high Fountain Grass.

In front of the Fountain Grass place masses of Juniper. Throughout this planting, place three Lilacs for height, and possibly a tree.

You can also include lawn. Many times people think of plantings only when landscaping a slope. However, another way to approach the design, is to plan on the area being mostly lawn with planting beds as part of the picture. For example, there might be a curvilinear planting bed which goes along the top of the slope, continues down the side, and then appears along the bottom. Imagine the letter "C".

The advantage of this, or something similar, is that lawn is relatively easy to care for. However, the plants create the interest.

Landscape Steps and Access Through Slopes

Landscape steps and walkways can be created through the lawn or planted areas. They can also be designed to go around the sides of the slope, rather than through it. If the path is going through the lawn, you can use stepping stones or a paving material, such as brick or pavers. You can also use nothing and walk on the lawn itself. This keeps the unity of the lawn and the open space, without breaking it up visually.

If the path is designed to go through planted areas, you can again use stepping stones or a paving material. You can also just have a mulched path. Loose stone is another option. A mulched or stone path (especially the loose stone) should be edged. You can use something as simple as steel edging or something more decorative as pavers on edge. Paths can be anywhere from two to four feet wide. Two feet wide paths are quite casual, while wider ones become a bit more important.

Terracing A Slope

One may terrace a slope to create a flat, usable area. A retaining wall may be created at the top, bottom or both. Lawn may then be used for sitting, play areas or extensive gardens. The usable area should range in grade from two to five percent. Please visit my detailed page on landscape retaining walls.

Landscaping steep slopes may seem daunting at first, but a very nice landscape can be created. Just remember to use drought tolerant plants. Cover the planting beds with a three inch deep layer of mulch. Consider installing a sprinkler system. Plan on dense plant coverage by including asses of groundcover to deter weeds. Include a large area of lawn for low maintenance.

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