Fire-Safe Landscape Design Explained

A fire-safe landscape is not a barren landscape.

“When a wildfire comes through your neighborhood, could your house survive on its own?” A dramatic question, but one we need to consider when living in an environment where wildfire is a common occurrence. “fire-safe landscape design” is a landscape that reduces house and property vulnerability to wildfire. The goal is to develop a landscape with a design and choice of plants that offers the best fire protection and enhances the property. The ideal is to surround the house with things that are less likely to burn. It is imperative when building homes in wildfire-prone areas that fire safety be a major factor in landscape design. Appropriate manipulation of the landscape can make a significant contribution toward wildfire survival.

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A fire-safe landscape design integrates traditional landscape functions and a design that reduces the threat from wildfire. It does not need to look much different than your traditional landscape. In addition to meeting a homeowner’s aesthetic desires and functional needs, such as entertaining, playing, storage and erosion control, a fire-safe landscape also includes vegetation modification techniques, planting for fire safety, defensible space principles and use of fire safety zones.

FireSafe Demonstration Garden

Through proper plant selection, placement and maintenance, we can diminish the possibility of ignition, lower fire intensity, and reduce how quickly survivability. In fire-safe landscape design, plant selection is primarily determined by a plant’s ability to reduce the wildfire threat. Other considerations may be important, such as appearance, ability to hold the soil in place, and wildlife habitat value. The traditional foundation planting of junipers is not a viable solution in a fire-safe landscape. Minimize use of evergreen shrubs and trees within 30 feet of a structure, because junipers, other conifers and broadleaf evergreens contain oils, resins, and waxes that makes these plants burn with great intensity.

Use ornamental grasses and berries sparingly because they also can be highly flammable. Choose “firewise” plants. These are plants with a high moisture content. They are low growing. Their stems and leaves are not resinous, oily or waxy. Deciduous trees are generally more fire resistant than evergreens because they have a higher moisture content when in leaf, but a lower fuel volume when dormant.

Simple diagram showing plants and vegetation for a fire-safe home

Placement and maintenance of trees and shrubs is as important as actual plant selection. When planning tree placement in the landscape, remember their size at maturity. Keep tree limbs at least 15 feet from chimneys, power lines and structures. Specimen trees can be used near a structure if pruned properly and well irrigated.

A fire-safe landscape uses driveways, lawns, walkways, patios, parking areas, areas with inorganic mulches, and fences constructed of nonflammable materials such as rock, brick, or cement to reduce fuel loads and create fuel breaks. Fuel breaks are a vital component in every fire-safe landscape design. Water features, pools, ponds or streams can be used also as fuel breaks. Areas where wildland vegetation has been thinned or replaced with less flammable plants are the traditional fuel break. Remember, while bare ground is an effective fuel break, it is not generally recommended as a fire-safe landscape element due to aesthetic, soil erosion, and other concerns.

A home located on a brushy site above a south or west facing slope will require more extensive wildfire safety landscape planning than a house situation on a flat lot with little vegetation around it. Boulders and rocks become fire retardant elements in a design. Whether or not a site can be irrigated will greatly influence location of hardscape (concrete, asphalt, wood decks, etc.), plant selection and placement. Prevailing winds, seasonal weather, local fire history, and characteristics of native vegetation surrounding the site are additional important considerations.

The 30 feet closest to a structure will be the highest water use area in the firewise landscape. This is an area where highly flammable fuels are kept to a minimum and plants are kept green throughout the fire season. Use well-irrigated perennials here. Another choice is low growing or non-woody deciduous plants. Lawn is soothing visually, and is also practical as a wildfire safety feature. But extensive areas of turfgrass may not be right for everyone. Some good alternatives include clover, groundcovers, and conservation grasses that are kept green during the fire season through irrigation. Rock mulches are good choices. Patios, masonry and rock planters are excellent fuel breaks and increase wildfire safety. Be creative with boulders, riprap, dry streambeds and sculptural inorganic elements. When designing a landscape for fire safety remember, less is better. Simplify visual lines and groupings. A firewise landscape lets plants and garden elements reveal their innate beauty by leaving space between plants and groups of plants. In fire-safe landscape design, the open spaces are more important than the plants.