Oaks ’n’ Folks – Volume 7, Issue 2 – September 1992
Urbanization in California’s oak woodlands is taking place at unprecedented rates. Areas that were previously extensively managed for livestock production, with only a few homes spread out over thousands of acres, now contain whole housing tracts. The distribution of homes and roads in the oak woodland landscape, road widths and standards, and the materials used in home construction, all have a major effect on the capacity of wildland fire fighting organizations to successfully protect homeowners from loss of property values. In addition, the distribution of fuel conditions conducive to major conflagrations is at historical highs due to years of fire exclusion, lack of maintenance of landscapes around homes, and failure of homeowners to follow required clearing standards set by state law. Location of homes adjacent to wildland areas, the so-called wildland-urban interface, puts homes in close proximity to wildland fuels.
The recent wildfires in oak woodlands in the East Bay hills and Santa Barbara are indicative of the kind of disasters that can occur in many oak woodland areas of the state as a result of the urbanization of these wildland areas. Some of the precautions that homeowners can take to reduce the risk they face from major wildfires are described below.
The State Board of Forestry recently established “Fire Safe” zoning requirements, which can help reduce future losses if enforced by local planning agencies. These recommend standards for: roads; spacing between houses; construction materials; water requirements; and fuel management.
California State Law requires clearance of flammable vegetation for 30 feet around the house. Flammable material is generally interpreted to include all dead vegetative matter and enough live crowns to avoid the spread of fire from one tree or bush to another. It is recognized that 30 foot clearance is seldom enough to protect a home from wildfire, and some local ordinances require 100 feet of clearance. Homeowners interested in minimizing the risk of wildfire should make the maximum possible effort to maintain clearance around the home.
Owners of homes in the oak woodlands are keenly interested in maintaining a good cover of oak trees because of the aesthetic and wildlife values they present. However, some effort will be required to minimize the danger of wildfire from overly dense or poorly maintained oaks. Trees should be thinned out so that their crowns are separated when they are full grown. Trees should be spaced out from the house itself, and under no circumstance should the tree overhang the house. Homeowners need to regularly clean their roofs and gutters of leaves, twigs, and other debris. Oaks around the home should be regularly pruned of dead wood. In addition, low hanging branches should be pruned off to avoid being ignited by a ground fire. Trees should be kept in as healthy and vigorous a situation as possible to minimize the fuel loading from dead or dying trees. Finally, owners need to be actively involved with their neighbors to ensure that these oak management practices are being applied on adjacent ownerships as well. This may be through a homeowner association, or through regular contact with public open space districts. It is important to be continually involved in thinning, pruning, and monitoring the oaks on your property to keep them as fire safe as possible.
In establishing landscapes in your oak woodland, you need to pay close attention to how this affects the fuel build-up around your home and around your oaks. Avoid creating fuel ladders between high bushes and oaks which allow ground fires to move into the crowns of the trees. Make sure that the crowns of bushes and trees are separated from each other. Use low-growing and fire-retardent plants under your oaks. Native and introduced ground covers and small flowering plants can be used. Plants with low volume and height, and low maintenance requirements, are most suitable. The reference listed below can help guide you on landscape plants that are compatible with oaks. You can also check with the local California Department of Forestry and Fire Protection office for suitable fire-retardent plants for your area.
California Department of Forestry and Fire Protection.1980. Fire safe guides for residential development in California. internal publication of CDF, 32 p.
California Oak Foundation. 1991. Compatible plants under and around oaks. Sacramento, CA. 69p.
Moore, H.E. 1981. Protecting residences from wildfires: a guide for homeowners, lawmakers, and planners. Gen. Tech. Rep. PSW-50, 44 p, Pacific Southwest forest and Range Exp. Station, U.S.D.A., Berkeley, CA.
prepared and edited by John M. Harper, Richard B. Standiford, and John W. LeBlanc