Fire Safety Garden
Fire Safety Landscaping
- Wildfires are a dangerous part of our natural cycle. Most native plants go dry and dormant during the summer drought. Small wildfires can quickly grow into blazing infernos, especially blown uphill in canyons and hilly terrain. Hot and dry Santa Ana winds create the perfect conditions for destructive fall fires.
Defensible space is the area around a house or building where plants and fuel are trimmed, reduced or cleared to slow the spread of wildfires.
You can minimize fire damage through good landscape design and garden maintenance. Every home is different. Your risk is greater if:
- your property slopes,
- Santa Ana winds blow towards your house from a natural area,
- your roof has wooden shingles,
- you have firewood, wooden fences, arbors, or gazebos close to your house.
The key is to design your Landscape to help defend your home. Create fire buffer zones around houses and buildings.
A fire-safe landscape has smaller, lower plants spaced farther apart. Smaller plants provide less fuel for fires. Use groundcovers, annuals, perennials, and low shrubs.
Control the spread of fires by creating open spaces between trees and large shrubs. Keep trees 30 feet apart and at least 10 feet between trees and large shrubs. In high-risk areas don't have trees or large shrubs near buildings. Tree branches should be farther than 10 feet from eaves or chimneys.
The safety or garden zone is the area within 30-50 feet of a building. The plants should be low-growing, fire-resistant, and use relatively little water. Keep the garden zone irrigated. In high risk areas plant sparingly next to buildings, using fire-resistant, low-growing plants and gravel or stone mulch.
The greenbelt buffer zone extends an additional 30-100 feet beyond the garden zone. Use low-growing, fire-resistant plants with a few widely spaced trees or Large shrubs. Your irrigation system should include this area.
The transition zone is where your garden meets a natural area. Remove or thin highly flammable plants Like native chamise or greaseweed, shrubby acacia, and taller eucalyptus. To avoid erosion don't dig up the roots. Cut the plants to the ground and spray an herbicide if necessary.
Wide driveways and space near buildings provide access for fire trucks and act as firebreaks.
In a really hot fire, all plants will burn. But some plants are more dangerous because they contain oils and resins that ignite quickly.
Select plants for fire safety with:
Small size (groundcovers, many annuals and perennials)
Choose popular plants like agapanthus, daylilies, Mexican bush sage, Indian hawthorn, star jasmine, pyracantha, pittosporum, oleander, euryops, or lavender.
High water retention (all succulents)
Use succulents including jade, aloe, agave, cacti, and some ice plants.
No oils or resins (avoid eucalyptus, pines, acacia, junipers)
Less Litter (avoid eucalyptus, pines, palms with dead leaves)
Low water needs
These California natives are fire-resistant: toyonr hollyleaf cherry, lemonadeberry, laurel sumac, and coyote brush.
Cleanup and cut back
Remove dead plants, leaves, and fallen branches. Clear debris from your gutters. Remove all dry grass and brush, dead branches, and Leaves from natural areas at the edge of your landscape. Chamise shrubs are highly flammable, so cut them to the ground before the fall Santa Ana season. Cut back dried or dead California sagebrush, black sage, and California buckwheat plants. Canyons and hilly terrain require more brush clearing than level ground.
Pruning slows fires
Reduce potential fuel: prune back or thin groundcovers, shrubs, and trees. Trim back shrubs under trees to keep fires from spreading up into trees. Remove lower branches of trees 6-10 ft. from the ground.
Watering and mulch
Well-watered plants resist burning and burn more slowly. Irrigation is most important within 30 feet of buildings. Extend irrigation systems up to 100 feet away, and even further on hillsides. Gravel, stone, and pebble mulches are good fire protection near buildings. (They also reduce weeds and watering.)
FIRE RESISTIVE CONSTRUCTION
The main elements of fire resistive construction include:
- Class A (non-combustible roof) such as tile
- Boxed eaves with screens
- Metal screens on vents to prevent the intrusion of firebrands or embers
- Address numbers should be reflective and easily seen from the street
- Non combustible wall material such as stucco
- Dual pane or tempered glass windows
- Chimney covered with a spark arrestor
- Driveway should be wide enough for easy access by fire apparatus
The following photo show the development of the miniature exhibit house. The house is designed to
withstand the elements as it will be in an outdoor environment. The house is made of construction grade materials and is expected to last for many years.
The garden around the miniature house demonstrates the elements of defensible space within 100 feet of the home.
What is defensible space?
Defensible Space is the area around a structure where combustible vegetation that can spread
fire has been cleared, reduced or replaced. This space acts as a barrier between a structure and
an advancing fire. Defensible space provides room for firefighters to do their jobs. Your house is
more likely to withstand a wildfire if grasses, brush, trees and other common forest fuels are
managed to reduce a fire’s intensity.
Zone 1 (within 30 feet of your home)
Plants should be fire resistive and not contain oils, resins or waxes
Prune vegetation away from the roof, chimney and driveway and keep gutters free of litter
Zone 2 (30 to 100 feet from your home)
Should have low growing fire resistive plants that are maintained
Maintain vertical and horizontal separation between plants and trees
Trim trees so branches are six feet from the ground
Remove dead trees
Why create defensible space?
Proper management of defensible space dramatically increases the chance of a home surviving a
wildfire and provides for firefighter safety as they defend structures.
The amount of defensible space around a home is directly related to a home’s ability to survive
How do I create defensible space?
- Plant fire-resistant, irrigated landscaping in the first 30 feet of the 100 feet from your structure.
These plants need to be maintained all year around.
- Keep natural vegetation in the remaining 50 feet of the 100 foot space. This would be the
area furthest away from your structure. The plants need to be thinned and cut back to no
more than 6 inches above the ground.
- You may need to do this several times a year since the plants grow back.
- Do not completely remove all vegetation which would leave the ground bare. Some
vegetation is necessary to prevent erosion. When native vegetation is removed for fire
control the bare soil is particularly vulnerable to soil erosion.
- Do not remove or disturb the existing plant root system to prevent any future erosion.
- Remove dead and dying vegetation.
- Trim trees that overhang or touch your structures.
- Properly irrigating plants will help prevent plants from igniting.
Trees and shrubs can be maintained by deep watering at least once a month for drought tolerant
species and once a week for high water requiring plants.
Residents who live in the wildland urban interface are encouraged to visit the miniature exhibit house at San Diego Botanic Garden to see how defensible space can be created while maintaining an attractive garden.
For more in-depth information about fire-safe landscaping, try:
Halsey, Richard W., Fire, Chaparral, and Survival in Southern California, Sunbelt Publications,
San Diego, CA, 2005.
Kent, Douglas, Firescaping, Wilderness Press, Berkeley, CA, 2005.
FOR MORE INFORMATION
Visit the City of Encinitas Fire Department website: www.cityofencinitas.org
Or contact your local fire department for vegetation management guidelines.
See the Native Plants and Native People Trail Page
See the Overlook Natural Area Page
Content: Courtesy FEMA
Photos: Rachel Cobb