We moved here because we love the forest…
Now we need to learn how to live within our Wildland Urban Interface (WUI) in a way that protects our homes and improves the health of the forest around it.
Living in a forest in today’s world of climate change has many of us feeling overwhelmed by the idea of reducing fuel loads on our land. But the key to defensible space is to start close in and move out. It is the reverse of peeling an onion and follows key permaculture principles of starting in the center and moving further and further out in concentric circles.
The goal of defensible space is to:
- eliminate pathways for a wildfire to burn directly to the home
- reduce radiant heat exposures
- reduce the potential for embers to ignite vegetation and other combustible materials adjacent to the home
- ensure access to your home for firefighters
- provide a safe place for fire personnel to defend the home and allow safe routes for evacuation.
Defensible space is the buffer you create between a building on your property and the grass, trees, shrubs, or any wildland area that surrounds it. Defensible space will help slow or stop the spread of wildfire and protect your home from catching fire – either from direct flame contact or radiant heat. Defensible space is also essential to help protect firefighters when they are defending your home.
Your home may be the most valuable investment you ever make. If you live in a high-risk fire hazard area, protect against the chance of losing that investment by creating defensible space and hardening your home.
Creating defensible space does not mean you need a ring of bare dirt around your home! Through proper planning, you can have both a beautiful landscape and a fire safe home.
Defensible Space Zones
Safer West County recommends homeowners utilize the “Home Ignition Zone” concept to make up the required 100 feet of defensible space recommended by Calfire.
Three zones make up the required 100 feet of defensible space:
- Zone Zero extends zero to five feet from structures, including the building itself, and should be completely free of combustibles.
- Zone 1 begins five feet from your house and extends 30 feet away. The most aggressive clearance is required closest to the structure. The main motto here is keep it green and clean within 30 feet. Remove dead and dying plants or branches. Water to keep plants thriving, not in stress. Plant with room between plants.
- Zone 2 lies beyond the home defense zone, extending at least 100 feet from the house or to your property line. Greater defense zone widths may be necessary if your home is on a steep slope or in a windswept exposure.
- The Access Zone, Zone 3, is adjacent to roads and driveways, fourteen feet overhead and ten feet from the edge of the roadway.
What is your legal responsibility?
Detailed descriptions of action that is legally required for each zone can be found here
Think small. Start today.
Just like with home hardening, there are many small things you can do today to improve your home’s fire resiliency.
- Move combustible materials away from your home. Look for wood piles, BBQ grill propane tanks, push brooms, and other items you might be keeping close at hand for convenience that might endanger your home.
- Trim trees to make sure no branches hang over your roof or chimneys.
- Prune back or transplant bushes from around your home to remove flammable debris in the first five feet around your home.
- Clean out your rain gutters and blow off debris from your rooftops.
- Remove dead leaves and branches from the first 30 feet around your home.
- Remove vegetation for 10 feet around your propane tanks.
Move wood at least 30 fee from your home.
Clear vegetation from around propane tanks.
Trim back vegetation in the first five feet around your home. Especially vegetation that comes up to eaves or over the roof.
Are there fire safe plants? Yes and no.
Use Fire-Resistant Landscaping
Look for plants with these characteristics:
- Able to store water in the leaves and stems
- Maintain high moisture content with limited watering
- Drought tolerant
- Low levels of volatile oils or resins
- Product limited dead materials
- Remove any dead portions of fire resistant plants.
While some plants are marketed and described as fire-safe or fire-resistant, all plants will burn
under the right conditions, regardless of how they are classified. The environment the plant grows in
and how it is maintained will generally have more influence on the flammability of the plant than how
For example, a plant with a good water supply could have a greener growth and hold leaves longer,
whereas a plant in a stressed or drought situation may have stunted growth and accumulated dead
materials. This can create a situation where the same species may be fire-resistant in one
environment and flammable in another. Some plants, such as a lavender, may initially have lush
growth and then several years later the growth may be woody and choked with dead materials.
Other plants may develop a dead thatch layer, under a green surface, that is highly combustible.
For more information about fire-resistant landscaping please visit readyforwildfire.org or visit your
local UC Cooperative Extension.
Characteristics and basic properties
Landscaping practices (or the pruning, maintenance, and cleanup) can have a greater impact on
whether a plant ignites than the type plant type alone. When bringing a fire-resistant perspective to
plant selection, consider the following:
- Does the plant has a higher moisture content in the leaves (as these leaves will be less likely
- Does the plant contain a lot of waxes, oils, and resins
- Does the plant have an open-growth structure
- How fast does the plant grow
- How tall will the plant grow
- Does the plant shed bark
Depending on where you want to locate the plant, a plant with more waxes, oils, and resins is likely
to be more flammable and release more heat energy when it burns. A plant that is more densely
structured can capture embers and may be more likely to ignite. A plant that sheds bark or branches
is likely to need more regular maintenance-related cleanup to reduce fuel accumulations at its
base. A plant that has a big leaf or needle drop will result in the need for more maintenance-related
cleanup to manage in your defensible space and on your roof or in your gutters. A plant that grows
quickly may exceed your expectations and challenge defensible space goals.
Native plants, pollinator friendly, or drought-tolerant plants can be good choices for those labelled
qualities, but they may or may not be any more fire-resistant than other plants.
As described in the defensible space section of this publication, placement is the most important
criteria when it comes to fire-resistant plant selection. Keep in mind that vegetation that touches the exterior siding, is located in front of windows, under eaves and vents, and/or under or near a deck will increase the likelihood that a home will be destroyed during a wildfire. By incorporating best management practices within 0-5 feet of a structure, thereby reducing
combustible vegetation and eliminating other combustible materials that an ember can ignite the
potential for direct flame contact to your house is reduced. By following the ideas in Zone 1, where
landscaping is separated into islands of vegetation and the continuity of plants is separated, the
odds increase for home survival from direct flame exposure. Additionally, all selected plants should
From a fire resilience perspective, vegetation management consists of good water management
practices, appropriate fertilization, and a regular practice of plant pruning and cleanup. With regular
watering, plant health increases and plants that are green and lush, are more resistant to ignition.
Drip irrigation can be helpful along with mulch for water conservation. Unfortunately, combustible mulches near to the home create an additional fire risk (Quarles and Smith, 2008). Eliminate combustible mulches within 0-5 feet from the home and recognize that from 5-30 feet, combustible mulch can expose the home to greater flame and ember contact. Rock mulch
will have greater fire resistance. Compost has a lower combustibility or low combustible rating and
may be a better alternative than combustible mulches when working 5 feet from the house and in the
5-30 ft. zone.
Eliminate Ladder Fuels
Resources to learn more…
Here are a few resources to help you start creating defensible space:
Explore our home hardening guidance.
Home hardening and defensible space go hand-in-hand. Learn more about ways you can harden your home today.