California native plants have remarkable characteristics that provide protective services to homes and structures during and after a fire. The massive canopy of a coast live oak can act as a shield for your home, extinguishing embers that travel miles ahead of a fire. Likewise, an evergreen ground cover such as coyote brush can help diffuse embers rolling towards your home. The deep roots of many species such as toyon can help stabilize slopes, preventing mud slides after a fire. With strategic garden design, careful plant selection, and proper maintenance, you can have a beautiful garden that is both resilient and habitat rich.
While this site offers general guidance, it is essential that you review and follow your local fire district codes, prioritizing their regulations over the information offered here.
Defensible Space is the area surrounding your home that can help protect it from loss or damage in a wildfire. Depending on your location, proximity to neighbors, terrain type, and habitat, Defensible Space is typically defined as a radius of 100ft surrounding a structure. Maintenance beyond 100ft does not make a difference for structure survival in a wildfire (Keeley et al. 2014).
Defensible Space is divided into different zones, starting with the home and radiating outwards:
- House: Before you invest resources into landscaping, the most important action you can take to protect your property is “Home Hardening.” Enclosed eaves and the presence of multiple pane windows are the most important factors in preventing structure loss (Syphard & Keeley 2019)
- 0 to 5ft: The Ember-Resistant Zone: The purpose of this zone is to prevent embers from gathering and igniting the home and to create space for firefighters to operate safely. Within this zone, there should be no vegetation.
- 5 to 30-50ft: The Home Protection Zone: The goal of this zone is to create an evergreen landscape that is irrigated and regularly maintained. Group low-growing vegetation into beds separated by paths to slow spread of fire to structures. The distance of this zone varies depending on the slope. Slopes with a 20% grade and above should extend to 50ft.
- 30-50 to 100ft: The Reduced Fuel / Thinning Zone: This zone creates habitat connectivity with surrounding wildlands while slowing fire. Plants in this zone should require little water and little maintenance. Plants should be spaced horizontally and vertically to reduce spread of fire from plant to plant (laddering).
Go deeper into Defensible Space! The most comprehensive and up-to-date resource for wildfire preparation in Southern California is Sustainable Defensible Space: Eco-appropriate Homescaping for Wildfire Resilience (SDS). The SDS was created by the Resource Conservation District of the Santa Monica Mountains with guidance from a technical advisory committee which Theodore Payne Foundation participated in.
No plant is fireproof, but some plants are harder to ignite than others. Evergreen plants which hold moisture are a much better choice than plants which are resinous, have volatile oils, accumulate dead wood, and/or have peeling bark. Getting started is easy!
- Evaluate Your Site Conditions: Use this guide to help identify soil type, hours of sunlight, and amount of space at your site.
- Identify Your Needs: Native plants offer many services such as erosion control and water conservation while offering beauty, habitat and a sense of place. Learn more about the services native plants provide here.
- Find Plants: Browse the SDS plant list. Consult TPF’s native plant database for details on planting and cultivation. Use Calscape’s advanced search options to find plants local to your area with desired characteristics.
Maintenance is a critical element of landscape management in high-risk wildfire areas. A manzanita can be an evergreen, ember diffusing ally or a fire hazard, depending on pruning and irrigation. Here are four essential aspects of maintaining a wildfire resilient landscape:
- Remove dead stems and leaves every year to reduce the fuel for fire. Living material is much less likely to catch fire from flying embers.
- Trim lower branches to keep fires from climbing trees and large shrubs. This is called “limbing up” and calls for pruning out the lower one-third of branches.
- Prune trees that overhang your house so that their branches are at least five feet above the roof and ten feet away from the chimney. (And don’t forget to clean your gutters!)
- Weed out invasive, exotic grasses that provide fuel for fires, and then mulch heavily to slow next year’s growth.
For a seasonal maintenance checklist, please visit Sustainable Defensible Space.
Up next: TPF’s Fire Story
This program was made possible in part by Edison International.
Illustrations by Edward Lum.