Published: July 26, 2013
The activity: Firewise landscape mitigation.
Why: Good landscape management can substantially reduce the risk that your home will burn in the event of a wildfire.
How: The approach is to create a defensible perimeter around your house where firefighters can safely protect your home.
During the Waldo Canyon fire in 2012, 54 percent of the structures that burned were ignited by embers carried by the wind to ignitable roofs or attics. Those risks are largely structural and will not be addressed in this article. Please consult the "CSFD Hillside Fire Mitigation Design Manual" to learn more about the ways to mitigate your risks by doing home improvement.
In terms of landscaping, the first thing to understand is that vegetation is wildfire fuel. Vegetative clearance around the house is a primary component of a home's ability to survive a wildfire. Any structure that is attached to a house is considered to be part of the house, including decks and fences. Creating a "fuel free" defensible space that is 30 feet around your home is one of the most important steps you can take to protect your family and home.
Start close to the house and work your way out. If possible, use rock mulch or hard surfaces within the first 3 feet to 5 feet of the structure. Vegetation closest to the home should be smaller, widely spaced and low growing. Plant in small, irregular clusters or islands, not in large masses. This breaks up continuity and creates natural firebreaks. Do not plant vegetation, or store firewood, under decks. Create fuel breaks throughout your landscape by using sidewalks, decorative rock, gravel and stepping stone pathways.
If you live on a large forested lot, continue to create a defensible space up to 200 feet from the house to minimize the radiant heat sources near the house. This will consist primarily of pruning and thinning trees, which will provide you with a healthier and more attractive landscape.
Avoid creating a fuel ladder. That's vegetation that provides the fire an ignitable path between the ground and tree tops. Shrubs and other low level plants can be a conduit for flame transfer from ground cover to larger plants and trees. Avoid heavy shrub plantings under trees. Make sure trees are pruned well above underlying plantings. The lower branches of pine trees frequently die as the tree ages, so remove those limbs. Never leave them lying in tall dry grasses.
Plant selection can be helpful. There are no truly "fireproof" plant species, so plant choice, spacing and maintenance are critical. In general, herbaceous plants and deciduous trees are more fire resistant than conifers. These plants hold more water and do not burn as fiercely as conifers, which contain pitch.
Tree selection is also key. Spacing away from the home is probably the primary concern when planting trees around your home. Consider the mature size of the tree when determining where to plant a tree. Deciduous trees are always a great choice in the defense space. Conifers can be incorporated in a firewise design but strategize how many to plant and where they can safely be located in the landscape.
When: Always monitor the fuel volumes available to fire. Remove annuals and perennials after they have gone to seed or when the stems become overly dry. Rake up leaves and other litter as it builds up through the season.
Get answers to you horticultural questions by calling a master gardener volunteer at 520-7684 or emailing CSUmg2@elpasoco.com. Volunteers are available Monday through Friday from 9 a.m. to noon.