Creating a Buffer Zone
As wildfires grow in intensity and frequency, so does the need for firescaping. Experts share tips for fire-safe plant selection, placement and maintenance.
With the threat of wildfire becoming more common around the country, planning a landscape with fire-resistant plants makes good business sense.
Photo courtesy of Green Scene Landscaping and Pools
Wildfires can happen anywhere. And they're getting bigger and occurring more often, with more than 500 homes destroyed just last month in Colorado Springs.
Enter the rise of "firescaping" - or fire-safe landscaping.
"Firescaping has grown as a trend, especially here in California, as homeowners have come to accept that we have a fifth season: fire season," says Scott Cohen of Green Scene Landscaping and Pools in Los Angeles. "And as information travels faster because of the Internet and live television broadcasts of devastating fires, there is more awareness of the fire hazards landscaping can present."
While no plant is fireproof, "firewise" plants like agapanthus can provide a lush and colorful buffer between structures and the line of fire. Seen here and below: Storm ™ lily of the Nile.
Photos courtesy of Tesselaar Plants USA unless otherwise noted
But firescaping isn't just for California and other typically hot, dry states anymore, with wildfires occurring in all 50 states this year. And in recent years, especially with winter droughts, warmer seasons and more severe storms causing arcing power lines, there has been no such thing as an isolated season of fire, says JoAnne Skelly, a firescaping educator with the "Living with Fire" program offered by the University of Nevada's Cooperative Extension.
That's why it's a professional growth opportunity for those in the green industry.
"You're missing out on a niche market if you don't explore this," she says. "Anyone can put in a landscape, but if you can be knowledgeable and credible about wildfire issues - especially in the western and southern United States market - you can make this into a really profitable knowledge area."
As firescaping becomes increasingly popular, so too have the number of plants identified or marketed as "firewise." Skelly warns, however, that such proclamations come via anecdotal evidence, not scientific testing, and that lists of such plants vary from state to state.
"We try to encourage people to use plants that are deciduous instead of evergreen, shorter instead of taller, herbaceous instead of woody and free of waxes, oils and resins," says Skelly. "We also recommend plants that produce little or no combustible materials like dead branches, needles and leaves."
Many of the traditional firescaping favorites include succulents like sedum, agave and yucca; groundcovers like carpet bugle, stonecrop and ice plant; perennials like irises, daylilies and coreopsis; shrubs like hydrangea, lilac and rose of Sharon; and trees like oaks, ash and maples. Turfgrass has also proved to be less fire-prone.
But there's no reason to settle for the typical when there are so many fire-resistant and retardant choices out there. Plant developer Monrovia, for instance, lists 812 firescaping or firewise varieties on its website, from agapanthus (lily of the Nile) like the sturdy Storm™ series, to cannas like the colorful Tropicanna® to fragrant phlox like the Volcano® line.
Some of Cohen's favorites include new twists on old standbys, like 'Hummel's Sunset', a colorful variegated version of Crassula ovata (jade plant or money tree); 'Sunburst' aeonium and 'Kitten Ears' tradescantia, which works well as a groundcover or in a hanging basket.
Placement, spacing and upkeep
In addition to plant selection, other firescaping strategies include removing flammable plants and other materials, designing more open space into the landscape, proper pruning practices and creating fire-safe or "defensible" space.
Cohen creates such fire-safe spaces by dividing the area around the home (or other structure to be protected) into concentric zones. The closer these zones are to the structure, the stricter the fire suppression guidelines.
Cohen calls the zone closest to the house "Zone 1." This area is reserved for the heaviest landscape editing, the most vigilant pruning and cleanup and the most fire-resistant plants. In his area, this includes agapanthus, pittosporum, California fuchsia, red hot poker and groundcovers like 'Pixie' gazania and red fescue.
"Zone 2 should have low-growing groundcovers and succulents to prevent ground fires from racing to Zone 1," continues Cohen. "Use colorful drifts of plantings like dwarf oleander, sedum, jade plant and miniature ice plant. Trees are OK if they are watered and spaced a minimum of 15 to 20 feet apart." Where Cohen lives, in Southern California, good choices include most oaks, California pepper and guava.
Zone 3, says Cohen, "should be a 50-foot-deep area with drought-resistant, reduced-fuel shrubs like rock rose, as well as well-watered flowers like yarrow and California poppies." In Zone 4, about 150 feet away from the house, he suggests focusing more on selective removal of fire-prone plants and the cleanup and pruning of what remains: "Trim plantings in order to create groups of natives 20 feet apart."
Fragrant phlox, such as these purple and white varieties from the Volcano® line, are good choices for adding sweeps of color.
Throughout the landscape, Cohen recommends vegetation-free strips as fuel breaks to slow or stop a blaze. "These can be decorative rock gardens, faux riverbeds, water features or decomposed granite walkways."
Sprinkler systems, he adds, also play a major role in reducing fire risk. "A combination of drip systems and low-precipitation overhead irrigation will keep plants filled with water and less likely to burn."
Watering, in fact, is a necessary deterrent to fires, says Skelly. "Keep plants lush, or as we say 'lean, clean and green,'" she says. "The closer you get to the house, the more vigilant you must be."
On the other hand, says Cohen, you should monitor irrigation to prevent the drowning of any drought-tolerant plants in your landscape: "That's the most common problem I see in the field."
Many bold and colorful herbaceous plants are suitable for firescaping installations, including varieties like Tropicanna® canna.
When planting trees, Skelly advises, keep in mind their mature height and width, maintaining limbs at least 15 feet away from power lines, chimneys and other structures.
"Less is better," she says. "Simplify visual lines and groupings. Create islands of plants with lots of open space between."
She also recommends a 30-foot minimum of defensible space around structures - larger if there's a slope; removing any dead vegetation; regular prunings at the appropriate times and maintaining a separation between layers of vegetation, to eliminate a "ladder of fuels."
By the numbers
In 2013 alone, wildfires have occurred in all 50 states, according to a May 30, 2013, report by the National Interagency Fire Center, a logistical and support center for U.S. firefighting based in Boise, Idaho.
"In the past 40 years," the center reports, "rising spring and summer temperatures, along with shrinking winter snowpack, have increased the risk of wildfires in most parts of the West." Continued climate change, the center predicts, will make wildfires much more common in the coming decades.
At press time, the Black Forest fire in Colorado Springs, which started June 11, had burned more than 14,000 acres, destroyed 500 homes - and killed two people. Although determined to be the most damaging fire in Colorado history, it was only one of nearly a dozen wildfires that have affected the state so far this year; six of them roared to life within the same week.
Land-use changes have also led to more wildfires as communities expand into previously unoccupied land, reports Climate Central, an independent organization of leading scientists and journalists researching and reporting climate change. Compared to the 1970s, the group's own research shows, wildfires bigger than 10,000 acres have occurred seven times more often, and those bigger than 25,000 acres have occurred five times more often.
The research also shows wildfires burning twice as much land each year as they did 40 years ago. In the past decade, the average annual burn area on Forest Service land in the West has exceeded 2 million acres - more than all of Yellowstone National Park.
"I advocate a hard pruning of trees and shrubs in fall to keep plantings from building up a lot of flammable wood," says Cohen. "Reducing fuel in our residential landscapes helps the firemen do their job when duty calls."
If you work in a fire-prone region-these days, that could be any of our 50 states-it's a good idea to familiarize yourself with the resources that can help you plan and maintain a firewise landscape. Following are just a few.
Lisa Hutchurson Lynch is media specialist for Tesselaar Plants. She can be reached at firstname.lastname@example.org.