Ultimately, every farm, orchard, and vineyard exists at the mercy of Mother Nature. For growers in California and much of the West, that’s rarely more apparent than in the ever-earlier, ever-longer wildfire season. This time of year, every hot, dry wind raises still-fresh memories of recent disasters like the Tubbs, Kincade, and Valley fires.
With large fires like these starting and spreading in forests and grasslands, agricultural land adjacent to natural areas is often at greatest risk. Damage can result not only from the flames, but from intense heat and smoke. (Many vineyards dealing with smoke taint in the aftermath of recent fires remain tied up in insurance and legal proceedings years after the fact.)
While growers may be powerless to keep their property out of a wildfire’s path, there are some concrete measures they can take to minimize damage.
Max Moritz, Ph.D., is a University of California Extension Specialist in wildland fire who studies fire dynamics. He recommends starting with the big picture: “Understand the hazard fire poses in your location and your particular vulnerabilities.”
Some of those fire vulnerabilities—and the hardening measures used to mitigate them—are common to any home or business: think heat-resistant glass windows and roof vent screens that prevent embers from blowing into attic spaces.
When it comes to preparing farmland itself for wildfire, growers should keep these three basic strategies in mind:
1. Remove fuel
Minimize combustible materials around buildings, trim landscape trees and shrubs, and always ensure that roofs and gutters are free from debris. University of California Extension Advisor Ben Faber, Ph.D., suggests removing broken limbs, deadwood, and all other combustible material from an area of 2 to 3 feet around tree trucks.
Know and weigh the fire fuel risks specific to your crop. “Avocado leaves, being thick and leathery, don’t decompose like other leaves,” Faber notes as one example. “Growers take advantage of this to suppress weeds, prevent erosion, and maintain moisture,” but excessive leaf litter can be a detriment in a fire.
2. Create defensible space
If possible, create buffers by trimming back vegetation and clearing wide fire breaks around your orchard or vineyard: between 30 and 50 feet is a good rule of thumb.
Extension Horticulture Advisor Sonia Rios suggests one additional step: “Mulching the cut vegetation into wood chips or scattered material can break up lateral and horizontal vegetative continuity, which reduces the rate of fire spread, fire intensity and flame height.”
3. Add moisture
During times of extreme and imminent fire danger, Faber recommends that growers run irrigation to “wet down the dry litter under trees, raise orchard humidity, and keep trees stress-free.” But, he notes, it’s important to check with the local fire department and ensure that doing so will not jeopardize firefighting efforts by reducing water pressure in nearby hydrants.
In an interview with SevenFifty Daily, Phil Coturri of Enterprise Vineyards notes a risk particular to drip irrigation systems: “The majority of the damage I’ve seen during fires is from the drip hose igniting and the plants going off as wicks,” he says. As stubble burns and smolders, Coturri says, “the hoses ignite and melt against the vine.” When possible, steel risers and pipes for above-ground irrigation systems may mitigate this risk.
Photo courtesy Cliff Walters
Clay Shannon of Shannon Ridge Winery is always mindful of wildfire potential and makes preparations ahead of fire season. His fuel reduction strategy includes a natural component: “One of our most important tools to keep vegetation short is our sheep,” Shannon says. “We run sheep on the non-crop areas surrounding the vineyard as well as through the vines.”
Following recommendations, Shannon also clears brush and keeps grass short for 30 feet outside their fencing. The winery even has firefighting equipment on-site. “We have a water truck and a dozer ready, as well as McLeod’s and shovels. We also maintain our buildings; roofs are kept clean, leaves and combustible materials are hauled away.” And, of course: “We pray a lot during fire season.”
Such extensive preparations for wildfire add to growers’ already full management schedules, but for those operating in wildfire-prone areas, preventive measures are essential. Years of care are required to cultivate a successful orchard or vineyard—and unchecked fire can erase the effort in a matter of minutes