The California Homeowner’s Guide to Defensible Space

Tue Dec 29 2020

If you live in California, chances are good that you’ve heard the term “defensible space” in the last few years.

And if you live in a state responsibility area, you’re likely aware that you are required to follow state laws for maintaining defensible space around your home.

In this guide, we’ll explain what defensible space is, how homeowners can maintain it with landscaping and other planning, and what its limits are. You should walk away with a clear idea of how to create defensible space around your home and where you can turn for further information.

What Is Defensible Space?

Defensible space is a way for California homeowners to lower their risk exposure to wildfires, which researchers Yvonne C. Barkley, Chris Schnepf, and Jack D. Cohen note are a natural part of the ecosystem in the West.

This means that, as with other destructive natural weather patterns, like hurricanes and tornadoes, homeowners who face wildfire risks must take steps to protect themselves and their property.

Maintaining defensible space is one of those steps. Defensible space is a barrier around a home that has two goals:

  1. To prevent wildfires (and other fires) from reaching the house.
  2. To give firefighters a safe buffer zone where they can fight fires near the house.

These two goals are related, of course: when it’s easier for firefighters to do their job, there’s a lower chance that a fire will reach your house. Then again, for fast-moving fires, you can’t always expect firefighters to arrive in time. In these situations, the defensible space itself may be enough to keep embers from igniting your home.

Defensible space itself generally consists of two zones, which form concentric circles around your house (and other relevant structures, like a garage). Collectively, the two zones create a 100-foot barrier around your home. Here’s a little more information:

  • Zone 1 is between 30 and 50 feet wide. In this zone, homeowners should eliminate dead plants, plant matter, leaves, and needles from the yard and gutters. Trees should be trimmed so that they’re at least 10 feet away from other trees and so that no branches overhang your roof or chimney. Large fuel sources (wood piles, propane tanks, etc.) should be moved out of Zone 1. Generally, there should be plenty of space between flammable vegetation and your house, deck, patio, porch, or garage.
  • Zone 2 is between 50 and 70 feet wide. In this zone, homeowners should keep grasses no higher than four inches and eliminate “ladder” plants – i.e., plants close enough together to transfer fire. That means creating both vertical and horizontal space between plants. Remove flammable plant matter from this zone, too (leaves, bark, pinecones, branches, etc.).

Figure 1 illustrates what Zone 1 and Zone 2 of defensible space might look like. Figure 2 illustrates what vertical spacing for plants might look like.

Figure 1 (Source)

Figure 2 (Source)

Worth noting: since 2008, new homes built in high fire-risk areas in California have had to meet fire-resistance criteria. It outlines which materials homes should be constructed with to minimize the likelihood that wildfires will ignite the property.

For example, metal screens are more fire resistant than fiberglass screens; slate roofs are more fire-resistant than shake or shingle roofs; and composite decks and porches are more fire resistant than those made from wood (obviously).

Defensible Space & Curb Appeal

There’s a myth that creating defensible space around your home will tank its curb appeal. Luckily, that’s only a myth.

In reality, the same defensible space that can protect your home and family from wildfires can also look beautiful to you and prospective buyers, if you decide to sell. See Figure 3 for an example of a home with defensible space landscaping that looks quite lovely.

Figure 3 (Source)

So how can you create a functional and aesthetically pleasing 100-foot border of defensible space around your home? Follow these landscaping tips and you should have no problems.

Landscaping for Defensible Space

First, a caveat: California is a big state, so best practices will vary a little based on where you live. But generally speaking, the following rules can help homeowners create defensible space around their homes:

  • Adjust for hills: If land slopes down from your home, know that your fire risk is greater and you may have to create a larger area of defensible space. Fires can reach uphill fuel (like dry plants) more easily, which means fire burns faster uphill. Plus, steeper hills increase the speed of the fire, which also increases its heat and intensity.
  • Think about prevailing winds: Fires typically follow prevailing winds, so familiarize yourself with how winds blow near you. Be sure to leave an extra cushion of defensible space on the windy side of your home.
  • Create space between plants: When plants are too close together, they make it easy for fire to spread. This is why it’s important to leave both horizontal and vertical space between plants in your landscape.
  • Choose the right plants: Trees with low resin or sap content burn less easily than those with higher contents. Plants like succulents with a high water content don’t ignite as easily as dry grasses. Generally, native plants tend to work better than non-native plants (more on the best plants for defensible space below). It’s also important to choose plants with deep roots, which will help prevent erosion after a fire, even if the tops of the plants are burned.
  • Include non-plant landscaping elements: Stone or rock walkways create both visual interest and a natural firebreak. Other stone and rock elements can both break up your plants and minimize your yard’s fire risk.

Choosing the right plants can have a big impact on the effectiveness of your defensible space, so it’s worth spelling out which plants tend to work best to minimize fire risk. Here’s a breakdown.

Plant Type Examples Suitable for defensible space landscaping?
Fire-resistant groundcover plants Ornamental strawberry Yes
Ignition-resistant plants Rockrose, ice plant, aloe Yes
Fire-resistant shrubs Hedging roses, bush honeysuckles, currant, cotoneaster, sumac, shrub apples, California redbud Yes
Conifers Pine, fir, cedar, juniper, redwood, spruce, yew, larch NO
Low-resin trees Hardwoods like maple, poplar, and cherry Yes
Drought-resistant native plants Red monkey flower, California fuchsia, California lilac Yes

Note: the best plants for your yard will also depend on your region. For detailed guidance on which plants to use in your yard to create defensible space, consult with:

Maintaining Your Defensible Space Landscape

In addition to adding the right plants to your homestead, you also have to remove plants and plant matter that could contribute to the spread of flames. One easy way to do that is by hiring a herd of goats to clear out your land.

That’s right, goats.

We talked to Scott Morris, co-founder of San Diego-based 805 Goats, about how bringing goats to your home can make the job of maintaining defensible space easier.

First of all, he noted, “They’re great for hilly terrain.”

If your land is mostly flat, it’s probably cheaper and faster to hire a human landscaping crew to clear away unwanted brush and debris. But if you have a hilly property, goats are likely the more economical choice (Morris estimated that his goats would cost about 30 percent less than contractors, but he also acknowledged that every property is different).

“They’re also quiet,” Morris said. “Oh, and they love poison oak and poison ivy. That’s a preferred vegetation for them. Those plants are like ice cream for goats.”

That’s important for homeowners with these poisonous plants on their properties: many landscaping companies won’t send workers out to remove those plants because contact with their oils can leave employees unable to work for weeks. And if you don’t feel like exposing yourself to the plants by clearing them yourself, goats are probably a good bet.

We also asked about rose bushes and other plants homeowners may not want goats nibbling on. Morris reassured us that they have a plan for that.

“We keep goats in the intended area by putting up a portable fence,” he explained. “The day before, we cut a fence line and put up a fence around the area where the goat herd will work. Then we move the fence as the goats work through the vegetation.”

Intrigued? Check out if you’re in the San Diego area, or do a quick search for landscaping goat herds near you if you live elsewhere in the state.

The Limits of Defensible Space

Defensible space is a crucial part of wildfire readiness in California, and maintaining defensible space is the law in many areas.

But it’s also important to acknowledge that there are limits to what defensible space can do. While it can reduce the likelihood that your house will burn in a wildfire, it is not 100 percent effective. Sometimes, even the best-maintained homesteads will burn.

We reached out to Chris Schnepf, the researcher whose work we quoted earlier, to ask whether he thought the current wildfire situation in California was a “new normal,” and if so, what that meant for homeowners.

“Fire is still fire,” he said. “But fire seasons are getting longer, and we still have a backlog of fuel accumulations to deal with in many regions of the West.”

He went on to say that, “Regarding homeowners, it’s more important than ever for their homes to be prepared to reduce ignition likelihood, especially from the larger fires that send lots of embers ahead of them.”

So vigilance remains important. And part of that vigilance is preparing for the worst-case scenario – that is, the times that your defensible space doesn’t prevent the spread of flames. In those situations, the wildfire insurance included in your homeowners insurance can help you rebuild and recover after the loss of your home.