Firewise Landscaping: Simple Steps to Reduce Your Risk

Feb 1, 2022

Fire is a real and present danger throughout California. Climate change has brought record periods of drought and excessive heat while decades of fire suppression practices have resulted in overgrown forests. Added to this dangerous mix is a rapid increase in human population at the edges of forested areas. The good news: there are things you can do to improve the odds that your home can survive a wildfire.

The Importance of Defensible Space:

Fire research shows that most homes are destroyed by wildfires when wind-driven embers land on flammable materials close to the structure. You can minimize the risk by creating a “defensible space” around your home which entails removing combustible materials immediately adjacent to your home and creating “zones” with landscaping designed to reduce opportunities for fire to spread while providing areas for fire fighters to safely defend your home.

Defensible Space Zone #1: This is the area immediately next to and within 5 feet of the home and includes any adjacent outbuildings and areas under attached decks and stair landings. Everything in this zone should be noncombustible. Good choices for this zone are rock mulches and “hardscaping” (paths, walkways, etc.) around the perimeter of the building. Plants, if any, should be widely spaced, low-growing, non-woody and herbaceous.

Defensible Space Zone #2: This is the area between 5 and 30 feet from the home. Key words for this space are “lean, clean, and green.” “Lean” means a limited amount of vegetation with adequate spaces in between. “Clean” means the area is kept free of dead, dry plant debris—preferably removed by means other than leaf blowers! “Green” means plants in this zone receive adequate irrigation during fire season. Good practices include incorporating organic soil amendments before planting to increase the water holding capacity of the soil and using rock mulches instead of highly combustible bark mulches.

Defensible Space Zone #3: This is the area from 30 to 100 feet from your home. (Note: If your property does not extend this far, please see strategies for working with neighbors below.) Here, the objective is to reduce fire from spreading inward toward the structures and to inhibit flames from moving upward into the crowns of trees. Actions to take include thinning trees so that branches are separated by at least 10 feet, removing dead or dying trees, branches and any piles of dry vegetation on the ground such as twigs, branches and large pieces of bark. For taller trees, prune the lower branches at least 10 feet up the trunk to reduce the possibility of flames climbing and connecting with the tree canopy.

Which plants to plant?

No plants are “fire proof” but there are plants that are fire-resistant, which are typically plants that are high in moisture. These types of plants store water in their leaves and stems and when subjected to fire conditions, can reduce the intensity with which a fire spreads by acting as “heat sinks.” They typically are slow growing, tidy and do well with limited watering due to deep root systems, which also helps to control erosion. Look for higher moisture plants with low levels of flammable oils and resins, an open branching habit and a relatively low volume of total vegetation. 

Many plants native to California meet fire resistant criteria. Because the plants have evolved over time in our local environment, they tend to be slower growing and therefore produce less fuel. They also require less maintenance and need less water. Here are a few natives to consider:

  • Annuals: Red Maids (Calandrinia mensiesii), Mariposa Lily (Calachortus venustus), and Tidy Tips (Layla
    platygloss).
  • Evergreen Shrubs: Bush Poppy (Dendromicon rigida), Lemonade Berry (Rhus integrifolia), Coffeeberry (Frangula californica), and California Lilac (Ceanothus-many forms).
  • Deciduous Shrubs: Flowering Currant (Ribes sanguineum var. glutinosum), Snowberry (Symphoricarpos albus), Mock Orange (Philadelphus lewisii)
  • Perennials: Douglas Iris (Iris douglasiana), Common Yarrow (Achillea millefolium), California Buttercup (Ranunculus californica), California Fuschia (Epilobium canum), Foothill Penstemon (Penstemon heterophyllus)
  • Large Shrubs and Trees: Coast Live Oak (Quercus agrifolia), Mountain Mahogany (Cercocarpus betuloides), Western Redbud (Cercis occidentalis), Western Sycamore (Platanus racemose)

What about the neighbors?

Most of us live in areas where conditions on one person's property can have major implications to the entire neighborhood in the event of a fire. So, what can you do to encourage your neighbors? Once you have implemented the recommended steps in Zones 1 and 2, reach out to all the residents in your immediate area. This could be in the form of an invitation to an outdoor picnic where a discussion about ways to protect the neighborhood can take place in a congenial setting. The invitation might also include preliminary fire safety information to provide everyone with background for the discussion. You can also ask representatives from your local fire department to attend and provide recommendations for the neighborhood. For residents who are unable to work on creating fire resistant zones around their homes due to physical or other issues, get a group together to help. Fire affects everyone so let's all do our part to protect our homes and property!

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This article was written by Master Gardener Cynthia Nations and edited by Master Gardener Maggie Mah.


By Maggie Mah
Editor
By Cynthia Nations
Author
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