A fire resistant roof is the most important fire safe preventive measure to ensure home survival in a wildland fire. Second most important is landscaping. In addition, in El Dorado County’s varied topography, home location can drastically increase danger from wildfire. Locating a structure on a ridge at the top of a “fire chimney” can create fire drafts that will make some homes extremely difficult to protect. Often home location may have been decided years prior to your ownership. Only landscape maintenance can reduce fire danger to these homes.
Of the various fire factors, landscaping is one of the most easily altered fire safe components. In more urban situations, choice of plant materials can greatly alter fire potential. In rural areas, management of existing native vegetation can greatly reduce fire danger. In either case, maintenance to remove dead branches, to mow dried grass, and to remove pine needles and leaves is crucial. Irrigation will generally reduce flammability, but may not be practical or economically feasible. Plants should be adapted to the elevation, soils, soil depth, soil moisture and shade found on your site.
Flame length (which determines danger to structures) is determined by both the mass of flammable vegetation and the continuity (both horizontal and vertical). The horizontal flame path can be broken by spacing the trees or shrubs 10-15′ apart, separated by cleared areas, walkways, rock or other low fuel materials. Vertical fuels can carry ground flames up into tree crowns. Cutting lower branches and thinning or removing shrubs and small trees below the canopy of mature trees will protect them from the “fuel ladder” effect. Plant species with finely divided leaves and dry, oily characteristics can be the most dangerous. The thick bark of mature conifers will resist most fires if the canopy can be protected.
After disturbance, aggressive wildland weeds may invade. Some are dangerously flammable (e.g. Scotch Broom) and many can be very uncomfortable (e.g. Starthistle). Even some landscaping plants can become serious fire problems (e.g. Pampas Grass). Other exotic weeds may crowd out native plants and degrade habitats (e.g. Alianthus, Himilayan Blackberry).
When planning your fire safe activities, consider potential wildlife habitat. In low, damp drainages with little fire danger, consider maintaining continuous vegetation for wildlife corridors. Animals need to hide from predators while traveling for food, water and mating. A variety of native species allows diverse wildlife species to survive and thrive among habitations.
Within the fire-safe zone around a home (minimum 30′, 100’+ on slopes), clumps of vegetation should be separate (10′ to 15′ apart), and all mature trees thinned from below to eliminate ladder fuels. “Flashy” fuels (dried grass and leaves) on the ground, should be separated from lower limbs. Remember, during a wild fire, fire fighters will need room to work with crews and equipment. If you make their job easier, your home may survive.
Talk to your fire department about fire safety. Check with UC Extension or your local ag department about invasive weed species. Consult the Sunset Western Garden book, Master Gardeners, and local nurseries about plant selection. Clear back roadside brush on access routes, and mark roads for firefighters. Rural living requires responsibility on your part.