GARDENING : Planting Ahead for Fire Safety
When a fire strikes your neighborhood, moments count. The longer you can keep the fire away from your home, the better your chances of saving your assets.
One way homeowners can buy time in a fire is to landscape with fire-retardant plants.
“Various plants have high moisture contents, which make them resistant to fire,” says Erik Katzmaier of Katzmaier Newell Kehr, a landscape architectural and architectural firm in Corona del Mar. “Sea fig, which is planted along the freeway, is 60%.”
Other fire-retardant plants include the strawberry tree, carob tree, pineapple guava, New Zealand Christmas Tree, pomegranate, oak, Brazilian Pepper, oleander, cape honeysuckle, dwarf coyote bush and many ice plants and other succulents.
Sometimes after a fire, these plants are still alive when everything else has been devastated.
“One house had a hillside with a large patch of dwarf coyote. While all the other plants burned, the dwarf coyote was just slightly singed. The fire went right up to it and stopped,” says Jon Anderson, hazard reduction supervisor for the Orange County Fire Department’s Fire Prevention Bureau.
Fire-resistant plants are not completely non-flammable. Many will burn eventually, but it takes an extremely high level of heat to burn them, and they tend to slow fires down. This offers precious time when your house is threatened.
In newly developed areas that border wildlands, the county Fire Department requires builders to landscape with drought-tolerant plants to create a greenbelt around homes. According to fire officials, these stringent requirements in new areas and changes in older neighborhoods have helped reduce fire damage in in recent years.
“We haven’t lost any Orange County homes in a brush fire in the last few years, even though we had 297 vegetation fires in 1990,” says Capt. Dan Young of the Fire Department.
“By taking every precaution possible in your yard, you provide firefighters with defensible space, which will enable them to work around your home,” says Young. “While firefighters want to save as many homes as possible, they also want to survive and will only work in areas that have some space. No matter how expensive a home is, if it is overgrown with vegetation, (firefighters) will try to save another house that has a better chance of surviving.”
To provide firefighters with defensible space in landscape, remove or thin fire-prone vegetation, add fire-resistant plants, clean up dead and dying plant debris, and irrigate properly.
Eucalyptus, junipers, sumacs, some pines, cedar, cypress, chamise, red shanks, California Sagebrush, Common Buckwheat, black sage, hopseed bush and fountain grass all contain a high oil content, which causes them to explode when fire hits them, sending hot embers flying. They are especially flammable in the summer months when they sweat and emit ether.
Because of their high flammability, experts suggest removing any of these plants from within 50 feet of a home. For those fire-prone plants you choose to keep closer than 50 feet, thin them out to lessen the chance of a fire spreading, experts say.
“Keep in mind that a fire takes the path of least resistance,” says Anderson. “If fire-prone plants are close together, a fire will quickly jump from one to another. Get rid of this ladder effect by thinning out these plants and interplanting with more fire-retardant varieties.”
Make the space between the fire-prone plants the same length as their height.
Within 50 feet of a home, plant fire-retardant plants that will form a “wet zone” and stop or at least slow down an approaching fire.
There are many attractive low-growing, fire-resistant plants, including ice plants, such as delosperma alba, which has white flowers; drosanthemum floribundum, which has pale pink flowers; and lampranthus spectabilis, a highly fire-resistant plant that comes in a variety of colors.
Other fire-resistant plants that are also good for binding slopes include cape weed, the prostrate coyote bush, which is also drought-tolerant, the trailing gazania, and the myoporum parvifolium, which makes an excellent coastal plant.
You may also want to plant larger drought-tolerant plants, such as the strawberry tree, manzanita, Western Red Bud, New Zealand Christmas Tree, pittosporum, carob tree, pineapple guava, myoporum, oleander, pomegranate, oak, Brazilian Pepper and Cape Honeysuckle.
The location and size of the yard will determine what is planted. If you live in a fire-prone area that has some land and hillsides, Fire Department regulations state that you should have a 20-foot setback zone from the house, then 50 feet of fire-retardant plants and a 100-foot area containing some flammable plants that are well-spaced and broken up by fire-retardant vegetation.
In a conventional neighborhood that is not prone to fires and has less land, keep vegetation 10 feet from a home.
“If your space is very limited and your land only extends 10 to 15 feet, plant fire-retardant plants in this area and keep them well watered,” says Katzmaier.
Don’t let plants dry out. The less water content they have, the more likely they are to burn. “The water department has moisture readers which will tell you what a safe moisture level is,” says Anderson. “While you do want to be careful of your water use, you don’t want your plants to become brown and dangerous.”
Although sprinklers will keep landscape irrigated and may be of some assistance during a fire, don’t depend on them.
“Sprinklers don’t safeguard you from fire,” says Anderson. “There may be high winds the day of the fire, you may not be home to turn the sprinklers on, or your water system could be shut off completely.”
Protect a home by not letting plants hang over the roof, especially those that easily ignite. Overhanging plants create easy-to-climb ladders for fires.
“A highly flammable plant hanging over a roof or lying against a house is a fire hazard,” says Anderson. “Not having a shake roof isn’t enough protection. Embers in the air will ignite such a plant quickly and set your house on fire.”
Another precaution in any size yard is to clean up dead and dying leaves and other debris.
“Even fire-retardant plants can burn if there is a lot of brown plant material surrounding them,” says Anderson. “Clean up under trees, shrubs and ground cover on a regular basis.”
Though there are no guarantees that you’ll avoid a fire, by properly organizing the landscape, you can minimize the chance of damage.
“You’re dealing with Mother Nature, and she can be unpredictable,” says Anderson. “All you can do is prepare your house in case a fire strikes.”
For more information on fire-retardant plants, consult the book, “Trees and Shrubs for Dry California Landscapes,” by Bob Perry, or call the Orange County Fire Department at (714) 744-0400. The department has a list of fire-retardant plants that includes planting diagrams.