Specialists in the fields of biology, forestry, and fire prevention have been studying fire retardance in plants for many years. The information gained from these studies is of importance to hillside residents who are faced with the direct threat to their homes and property from chaparral brush fires.
The most effective protection a hillside homeowner can have is a wide zone of bare ground separating his property from the native brush. Such a zone, however, is usually not desirable aesthetically. Furthermore, bare ground is extremely vulnerable to erosion and mud slides during the rainy season and is hot and dusty during the summer dry season. The selection of plants for use in hillside residential areas is, therefore, of concern to the homeowner. Beyond personal aesthetic preference, consideration should be given to other factors such as low fuel volume, relatively high degree of fire retardance, good root system for erosion control, and cultural and maintenance requirements.
After removal of the highly flammable native shrubs, which are drought resistant, selection of landscaping plants depends a great deal on water availability. The installation of permanent, automatic sprinkler systems not only will broaden the selection of plants, but will also increase fire retardance in the plants. A proper maintenance program to minimize the build-up of dead branches and leaves and to eliminate unwanted weeds will provide additional fire insurance for hillside property.
For a list of 30 recommended shrubs and herbaceous perennials, primarily ground covers, for planting in hillside residential areas, email or call the Vacaville Fire Department at 449-5453. The recommendations are based on two criteria: 1) relatively high moisture capacity and 2) prostrate or creeping growth habit. Although many other plants with similar characteristics could have been listed, these have been selected because of their established horticultural value and ready availability through most nurseries.
DROUGHT TOLERANCE and EROSION CONTROL
Drought tolerance is evaluated in terms of the ability of each species to withstand summer drought conditions. The water-retaining mechanism within the plant tissue as well as the depth and efficiency of the root system all contribute to the total tolerance of the plant to drought. Even the most drought-tolerant species must have some summer water, however, to keep the moisture content of the tissue as high as possible. The value of a plant in controlling soil erosion on hillsides depends to a certain degree on the steepness of the slope.
General maintenance requirements must be provided to keep a planting in a relatively low fire-hazard condition. Maintenance includes such operations as pruning, renovation, weed control and removal of litter. Without proper maintenance, any planting could become a fire hazard given enough time. Since no two hillside landscaping situations are exactly the same, no formula governing what and how to plant can be given. Further information on slope conditions, cultural requirements and other plants to use for specific purposes can be obtained from the City of Vacaville Landscape Architect at 449-5170.
Brush fire prevention in hillside residential areas of Vacaville and the role of fire-retardant plants as a barrier or "green belt" around the home can be summarized as follows:
- Removal of all or most of the highly flammable native brush from the perimeter of the house for a distance of not less than 100 feet.
- Replanting of cleared areas predominantly with low-growing plants having a relatively high moisture capacity. Plants having these characteristics are considered to be fire retardant.
- Proper watering throughout the dry fire season to maintain a high moisture content, and therefore, a high degree of fire retardance in the plants. A permanently installed, preferable automatic, sprinkler system is recommended.
- Maintaining the planting to remove weeds and to minimize the accumulation of dead branches and leaves thereby keeping the fire hazard low.
THE GREEN BELT CONCEPT OF FIRE PREVENTION IS EFFECTIVE ONLY TO THE EXTENT THAT THE HOMEOWNER IS WILLING TO FOLLOW ALL OF THESE RECOMMENDATIONS!