The defensible space of a firewise landscape is divided into three treatment zones, which increase in fire resistance as you get closer to your home and structures. A minimum treatment area of 100 feet is recommended for homes and outbuildings on flat ground, and up to 200 feet or more on sloped sites. This is because fire behaves differently on slopes and in draws than it does on flat areas. For more information on fire behavior go to the Science of Fire section.
Your defensible space is the area that includes your home and its immediate surroundings, and is where you have made a concentrated effort to reduce the chance of an ignition by wildfire or flaming embers. Defensible space starts with your home and moves out into the landscape from there. In areas with homes that are close enough to each other, defensible spaces may overlap to provide added protection for the subdivision.
Zone 1. Your Home (the red zone).
In zone 1, steps have been taken to decrease and/or eliminate the ignition potential of your home. Particular attention is paid to non-flammable roofing, enclosing soffits and overhangs, removing debris from roofs and gutters, and identifying flammable items such as patio furniture, brooms, flowerboxes, doormats, etc. For more information on how to make your home more fire resistant go to the Firewise Building Materials section.
Zone 2. Your landscape (the yellow zone).
In zone 2, the home is surrounded by a greenbelt of well-watered and maintained plant materials. Perennials, ground-covers, and annuals are planted in groups with individual trees and shrubs. These islands of vegetation are surrounded by rock or brick retaining walls and well-watered turf. Firewood and propane tanks are placed on gravel or concrete pads. This zone requires yearly removal of overgrowth and dry debris on the ground, as well as pruning trees.
Zone 3. Beyond 100 feet (the green zone).
Zone 3 is composed of native vegetation that has been thinned. If possible, highly flammable species of trees and shrubs are removed and replaced with less-fire-prone species.