The most important is to create a defensible space around the house perimeter. Ideally, you should have a 30-foot “free zone” from all buildings, structures, and decks. This space gives firefighters room to their job if needed. Often firefighters will bypass a home that has little to no defensible area in which to work, opting instead for one they think they will be more likely to save.
If at your place it isn't practical to remove all vegetation, it is extremely important to remove any dead plant material — dry leaves, pine needles and highly flammable plants such as Italian cypress, pine, fir, spruce, eucalyptus, junipers, palms, Japanese honeysuckle and some ornamental grasses.
Create fire-safe zones by building concrete or stone patios, walkways, and walls. Flower beds, gardens, appropriate ground covers and mulch placed near your home can also serve as a fire-break.
Removing highly flammable plants and replacing them with fire-resistant options is highly recommended — especially if you live in a high-fire zone.
What makes a tree or shrub fire-resistant? If it's non-oily, deciduous (drops its leaves in winter), large leaved and/or has high-water content. These fare best when exposed to high heat or fire. To ensure that your plants are as fire resistant as possible, make sure they're healthy, well hydrated and free of dead wood.
Excessive vegetation adds fuel to a flame. The plants nearest your home should be widely spaced and low-growing. Avoid large masses. Instead, plant in small clusters using a wide variety of species. Here are some fire-resistant options to consider:
Trees: California live oaks, native redwoods, California bay laurel, maples, citrus, cherry, apple, strawberry tree, dogwood, ash, loquat, ‘Little Gem' magnolia, toyon, white alder, weeping bottlebrush, redbud.
Large shrubs: Aloe, ceanothus, cotoneaster, escallonia, currant, pineapple guava, flowering quince, Island bush poppy, Pacific wax myrtle, photinia, pittosporum, mock orange, plumbago, podocarpus, laurel, viburnum.
Flowering plants: Azalea, camellia, hibiscus, lavender, monkey flower, California fuchsia, coral bells, society garlic, salvia, rhododendron.
Ground covers: Woolley yarrow, Ajuga reptans, purple rockrose, creeping coprosma, creeping thyme, ice plant, mock strawberry, wild strawberry, evergreen candytuft, lantana, Lamium, African daisy, wooly thyme, star jasmine, sedum.
Vines: Trumpet vine, potato vine, Cape honeysuckle.
Mulching around your trees and shrubs will help them retain moisture, reduce weeds and provide nutrients to the soil. However, if you are in a high fire area, avoid using wood chips and or pine needles, which can feed a fire. If you do have wood-based mulch, make sure to keep it moist, and add a layer of compost on top. Using compost by itself or layers of rocks or pebbles might be a better choice.
Raging fires can produce extremely high heat. Investigators of the 2008 Trabing Fire near Watsonville reported that temperatures had reached more than 3,000 degrees. Unfortunately, no plant would survive that!
If there is a fire near you, please heed the advice from your local fire authorities and evacuate if and when you are asked to do so.
by UC Master Gardener Rebecca Jepsen
Photo: Rebecca Jepsen
This article first appeared in the August 17 issue of the San Jose Mercury News.