All of california is at risk for wildfires. Once there was a 'wildfire season' but now the possibility of wildfires stretches across most the year. Creating defensible space is important to improve your home's or commercial property's ability to survive a wildfire. It’s the space you make between your property's buildings and the surrounding area of landscape. This space is broken down into two zones which act as a buffers between your surroundings.
The buffer zones are essential to help prevent the spread of fire to your property. Defensible space is important to give firefighters a chance to properly defend your property and to increase their safety while doing so.
100 Feet of Defensible Space Required by Law
Back in January 2005, state law became effective that extended the defensible space clearance around homes and structures from 30 feet to 100 feet. Studies showed that proper clearance to 100 feet dramatically increases the chance of your house surviving a wildfire.
Defensible Space Zones
Two zones make up the required 100 feet of defensible space. California Department of Forestry and Fire Protection and ReadyforWildfire.org have great tips to create a “LEAN, CLEAN and GREEN ZONE” by removing all flammable vegetation within 30 feet immediately surrounding your home. Then create a “REDUCED FUEL ZONE” in the remaining 70 feet or to your property line.
Zone 1 extends 30 feet* out from buildings, structures, decks, etc.
Remove all dead plants, grass and weeds (vegetation).
Remove dead or dry leaves and pine needles from your yard, roof and rain gutters.
Trim trees regularly to keep branches a minimum of 10 feet from other trees.
Remove branches that hang over your roof and keep dead branches 10 feet away from your chimney.
Relocate wood piles into Zone 2.
Remove or prune flammable plants and shrubs near windows.
Remove vegetation and items that could catch fire from around and under decks.
Create a separation between trees, shrubs and items that could catch fire, such as patio furniture, wood piles, swing sets, etc.
Zone 2 extends 100 feet out from buildings, structures, decks, etc.
Cut or mow annual grass down to a maximum height of 4 inches.
Create horizontal spacing between shrubs and trees. (See diagram)
Create vertical spacing between grass, shrubs and trees. (See diagram)
Remove fallen leaves, needles, twigs, bark, cones, and small branches. However, they may be permitted to a depth of 3 inches.
* San Diego County requires 50 feet of clearance in Zone 1. Check with your local fire department for any additional defensible space or weed abatement ordinances.
Plant and Tree Spacing
The spacing between grass, shrubs, and trees is crucial to reduce the spread of wildfires. The spacing needed is determined by the type and size of brush and trees, as well as the slope of the land. For example, a property on a steep slope with larger vegetation requires greater spacing between trees and shrubs than a level property that has small, sparse vegetation.
Remove all tree branches at least 6 feet from the ground. Allow extra vertical space between shrubs and trees. Lack of vertical space can allow a fire to move from the ground to the brush to the tree tops like a ladder. To determine the proper vertical spacing between shrubs and the lowest branches of trees, use the formula below.
Example: A five foot shrub is growing near a tree. 3×5 = 15 feet of clearance needed between the top of the shrub and the lowest tree branch.
Horizontal spacing depends on the slope of the land and the height of the shrubs or trees. Check the chart below to determine spacing distance.
Our team at Pacific Vista Landscape Services can help your home or commercial property meet the Defensible Space requirements. Call us today for a free estimate and see what we can do for you!
Here are other helpful articles on defensible space:
Fire Resistant Plants for Southern California
Seasonal Ways to Reduce Wildifre Risk