As a homeowner in the wildland/urban interface (WUI), you have the primary responsibility for reducing your home’s vulnerability to wildfire. By using Firewise principles and practices, you give yourself a huge advantage. Not only will you decrease ignitability, but you also will affect how a wildfire behaves on your property.

Surrounding yourself with a strategically designed, lush, beautiful, and well-maintained landscape is your best defense. Firewise landscaping is simple in principle and revolves around minimizing and rearranging fuels.

In this section you will learn

• what defensible space is and how to use it.
• the principles behind Firewise landscape design.
• the characteristics of Firewise plant materials.
• how to maintain your Firewise landscape.

Defensible Space 

Defensible space is the natural and landscaped area around a structure that is designed and maintained to reduce fire danger. Defensible space is all about minimizing and rearranging fuels. By treating fuels around your home and outbuildings, you influence wildfire behavior, thereby decreasing ignition potential.

Defensible space not only decreases your home’s vulnerability to wildfire, but can provide firefighters a safe environment in which to defend your property. Where homes are close to each other, defensible spaces may overlap to provide added protection for the neighborhood.

A minimum defensible space of 100 feet is recommended for homes and outbuildings on flat ground—up to 200 feet or more on sloped sites. Defensible space is commonly divided into three zones.

Defensible space is divided into three zones.

Zone 1—Your Buildings and the First 5 Feet (Clean and Green)

The ignition zone begins with a structure and extends 5 feet out in all directions. Aside from the roof, the first 5 feet surrounding your home and outbuildings present the highest wildfire risk.

In Zone 1, take steps to decrease and/or eliminate ignition potential. Remove highly flammable shrubs such as junipers, and replace them with low-growing, Firewise plant materials, well-watered turf, and/or nonflammable mulch. Remove combustible materials, such as bark and leaf/needle litter, as they accumulate.

Zone 2—From 5 to 30 Feet (Pruned and Groomed)

Zone 2 should consist of a well-maintained greenbelt. Surround islands of Firewise plant materials with rock or brick retaining walls and/or well-watered turf. Place firewood and propane tanks on gravel or concrete pads at least 30 feet away from structures and surround them with nonflammable fencing.

Zone 3—100 Feet and Beyond (Natural vegetation)

Zone 3 is composed of native vegetation. Thin trees to a 10- by 10-foot or 12- by 12-foot spacing. If possible, remove highly flammable vegetation and replace it with Firewise species. Maintain Zone 3 by yearly thinning and pruning, removal of dead and dying plants, and periodic fertilization and irrigation, as needed.