Landscape Structures

Most libraries, bookstores, and garden centers offer a variety of publications that contain detailed construction plans and material suggestions for landscape structures. We discuss only the more common structures in this article. 

Grading 

If your home site is already graded and even partially landscaped, you probably won’t want to change its contours. But if the final grading has not been done, you may be able to create the topography most appropriate for your landscape design. 

Actually, the best time to think about changing a home site’s topography is before building begins. This is also the best time to decide whether shade trees and other plants already there should be saved. Mature trees and shrubs add thousands of dollars of value to residential properties. 

If you want to keep existing plants in your landscape design, they should be protected before construction begins. Construction equipment can damage and kill trees by compacting soil in their root zones. A simple fence erected just beyond the branch spread of a tree will protect both roots and trunk from damage. 

If you change the grade around an established tree, you must avoid changing the amount of air, water, and soil nutrients reaching it. See the Extension publication Preserving Trees During Construction (A3072) for details on how to accomplish this. 

During rough grading, the topsoil should be stockpiled away from the immediate construction site. To protect this valuable soil from erosion for a short time, spread weed-free straw over it or cover it with plastic tarp. If the topsoil is to be stockpiled for more than one season, seed the pile with annual rye grass, oats, or another annual plant. When construction is completed, the compacted soil should be aerated first, then have at least 4–6 inches of topsoil spread evenly over the lot. 

Mounds, berms, and changes in ground contour great enough to require steps or retaining walls help create an interesting landscape. But they should perform a specific function, such as outlining specific use areas or other lawn spaces, buffering noise, or screening unwanted views. Mounds should blend into the surrounding topography and look natural. 

Your ground elevation must match your neighbors’ at lot lines. You can accomplish this with gradual grading or retaining walls. 

Hardscapes 

Hardscapes include structures in the landscape that tend to be permanent or semi-permanent features, including driveways, walkways, steps, decks and patios, retaining walls, fences, and lighting. They can be built out of several different materials and can add to the artistic value of your property. Materials such as brick, flagstone, permeable pavers, crushed stone, and cement are commonly used in hardscapes. It is best to use similar building products throughout the landscape rather than mixing many different types of materials. You may need to check local ordinances or obtain a building permit prior to construction. 

Driveways 

The driveway is an integral part of a home’s public area, providing access for both vehicles and pedestrians. At most homes, it is where visitors arrive, mail is delivered, trash is picked up, and children play. It should be wide enough to accommodate pedestrians and vehicles at the same time. If you have enough space, consider constructing a turn court and parking area to permit the unhampered and safe movement of vehicles. 

For safety, the drive should meet the street at a right angle, and plants or structures must not hamper a driver’s vision. If the drive has a steep grade, try to design a nearly level area near the garage and at the street intersection. 

Driveways should have a slope of at least 1% (1 foot rise per 100 feet traveled) for proper drainage. But a slope of more than 10% will be hazardous in winter. Remember to provide space where snow can be placed in winter without damaging plants or structures. 

We recommend that homeowners seek professional help to make sure that unusually long driveways or those on steep grades fit harmoniously into the landscape.

Walks 

Most people find walks already in place when they move into a home. A curved walkway has much more curb appeal than a straight walkway. Typically, an entrance walk meets the driveway at a right angle and parallels the house’s front door. Unfortunately, in many cases the walk is too narrow for comfortable pedestrian use and too close to the house for proper plant growth. 

An entrance walk should be at least four feet wide. A large house may require a five-foot walk for proper scale. If you have the opportunity to plan your entrance walkway, leave at least four feet between it and the house. The more space the better to provide enough room for an entrance planting to accent the front door. 

Plan the entrance walk for easy access and winter snow removal. A slope of 1–4% is ideal. For safety, the slope should be no more than 6%. 

Steps 

Where the ground slopes more than 6%, you will need to install steps to permit people to move from one level to another. No matter what the steps are constructed of, they should meet a long-established standard for safe and convenient outdoor steps: two risers (the riser is the vertical part of a step) plus one tread (the horizontal part) should have a combined measurement of 26 inches. The most common step dimensions are 51/2-inch risers with 15-inch treads and 6-inch risers with 14-inch treads. 

A pedestrian may not notice only one or two steps, so as a rule a set of steps should have at least three risers. If this isn’t possible, use an eye-catching surface material or outdoor lighting to make the steps visible. Handrails make steps safer, especially in winter. 

Decks and patios 

If you want a deck or patio for outdoor living, plan for it carefully to make it useful in as many ways as possible. Decks and patios should be an extension of your home and easily accessible from both your yard and from inside the home. 

Location is one important consideration. A patio or deck should be convenient to the appropriate areas of your house. If you plan to eat or entertain there, place it near the kitchen or family room. Of course, door locations may limit your placement alternatives. Other factors to consider are exposure to sunlight, summer winds, good views, and privacy. 

Patio size will depend on what you want to use the patio for, yard space available, and family size. About 64 square feet of hard-surfaced patio space for every family member is recommended. 

A patio should have a 1–2% slope away from the house so water will drain away from the house. 

A deck can provide a level outdoor area over steep ground. It should appear to be an extension of the house. Its color and texture should harmonize with the house and surrounding landscape. 

The architectural lines of your home, choice of construction materials, and other aspects of your landscape design will all influence the shape of a patio or deck.

Retaining walls 

Retaining walls are used to make abrupt changes in elevation, provide privacy, and delineate outdoor space. Stone, brick, wood ties, timbers, and concrete are the most commonly used materials. 

For steep grade changes, a series of low terraced walls is usually better than one high one. The higher the wall, the more it must be reinforced to withstand the pressures created by soil and moisture freezing and thawing in winter. 

For both dry and mortared walls, careful planning and construction are essential. Consult detailed design books or seek professional assistance if you plan to build a retaining wall more than four feet high. 

Fences 

Fences, alone or in combination with plantings, provide privacy and enclosure in the home landscape. They also serve as windscreens, screens for poor views, accents, space dividers, sources of shade, and backdrops for plants. 

Fences may be constructed in a variety of styles and from many different materials. If you decide to build a fence, choose a style that complements your overall landscape design. Chain-link fences, with or without plastic strips, rarely beautify a yard. Fences made of dark or neutral-colored natural materials usually do. 

Lighting 

Outdoor lighting can be included in your landscape design. Lighting walks, entrances, and steps makes them safer, especially during dark and slippery winter months. Soft, down-facing overhead lighting extends the useful hours of patios and decks. With lights, you can highlight particular plants or structures. Low landscape lighting—no more than three feet from the ground—can enhance your entire landscape ambiance in the evening.