From the Memsahib: Developing Wildfire Defensive Space at Your Home or Retreat

Much of the western U.S. is starting to look dry as the Spring rains are over in many areas and the annual grasses have already gone to seed and turned brown. With major fires burning in several states, it seems timely to discuss the”defensive space” of your property. [JWR Adds: Not to be confused with “ballistic” defensive space, which I recently addressed in SurvivalBlog.] The goal is to prevent a forest fire from reaching your house by reducing the amount of fuel for a fire near your home. When forest fires lack fuel crown fires drop to ground fires. Ground fires burn slower and are easier to contain. The recommended defensive space plan divides the area around your house into three zones.

Zone One is 0-to-15 feet all around your home. It is recommended that you have no trees and no large shrubs in this zone if you live in an area prone to wildfires. If you do have landscaping close to your house, then it should be a plant species that is not readily combustible. Succulent groundcover plants are recommended. Better yet would be decorative rocks! The idea is that there should be no organic fuel within 15 feet of your home.

Zone Two is 15-to-75+ feet area around your home. In this area it is recommended that trees are spaced so that there is a ten feet space between the outermost edges of the branches of each tree. This means large trees might need to be spaced 30 or 40 feet between the trucks of the trees. The purpose is so that a “crown” forest fire would not be able to jump from crown to crown within your defensive space. You do not want to give a ground fire a “ladder” to climb into the crowns of your trees, so it is recommended that you remove all the limbs which are within 10 feet of the ground. You should also not allow thick underbrush to grow around your trees which could feed a fire and also serve as a ladder. Note that if your house is on a hillside, then Zone 2 might be as far as 125 feet downhill.

Zone Three is from the outer edge of Zone Two to the edge of your property. (Zone Three was described by one web page as “an area of traditional forest management and is of no particular size. It extends from the edge of your defensible space to your property boundaries.”)

By the time you have created a proper defensive space around your home the landscaping is not going to look too “natural”. It will be much more like a town park than a natural habitat. But, that is a sacrifice I’m willing to make in order to defend our home against forest fires.