Fire Resistant Landscaping For Your Home Garden Garden Notes
We live in an increasingly wild and urban interface, where housing meets wild forests and rangelands. Warmer, drier weather and stronger winds create an increased risk of forest fires.
Gardeners have the opportunity to reduce the vulnerability of their homes and neighborhoods to forest fires. âSurrounding yourself with a strategically designed, lush, beautiful and well-maintained landscape is your best defense,â according to the nonprofit Idaho Firewise.
Fire-resistant landscaping is based on two simple principles: creating a defensible space around the house, and smart plant selection and maintenance.
Defensible space refers to an open area around a structure to reduce fire growth and provide a safe area where firefighters can work. David Seabrook, East Jefferson District 1 Fire Marshal and WSU Extension Master Gardener, shares a few simple steps to create and maintain this defensible space.
First, remove potentially hazardous materials, debris, and dead trees or shrubs near the house. Keep the roof, gutters and gutters free of dry twigs, leaves and needles. Store firewood and other combustible materials well away from buildings. Keep weeds and other debris away from propane tanks and sheds where gasoline or other fuels are stored. It is also essential to have a hose or other easily accessible water source.
If you have mature trees near the house, prune the branches about 10 feet above the ground and 10 feet above the undergrowth vegetation. Remove tree branches within 15 feet of roofs and chimneys.
Remove “ladder fuels” – small trees that can act as fire ladders and carry them to the tops of larger trees. Thinning of these small trees, as well as general thinning of the woods, is best between August and December to avoid creating a habitat for bark beetles. (Beetles become active at the end of winter and look for fresh slash and damaged trees.)
If you have piles of slash from pruning and thinning, shred them to break down or take them to the county’s green recycling program.
“These are recommendations that gardeners must take into account,” Seabrook said, adding that “each of us must decide which risk factor we are willing to accept, knowing that our decisions will affect our neighbors and our neighborhoods.”
Placement and maintenance of plants is just as important as plant selection. For the area within 30 feet of your home, use slow-growing, fire-resistant plants, ground covers, or grass that is well watered and mowed low to the ground. Group the plants into “islands” and create fire breaks, which are holes in combustible vegetation to slow the progress of a fire. These can be gravel paths, bodies of water, rock faces or stepping stones.
Seabrook shared a few examples from his own property. Mature trees that grew under the eaves and near the front door were removed and replaced with smaller native rhododendrons and ground covers. Conifers within 30 feet of the house have been replaced with blueberry plants. For emergency preparedness as well as fire resistance, “a well-cultivated garden with food crops is a great option,” Seabrook added.
Note that bark mulch or “beauty bark” is flammable and should be replaced, if possible. Tree shavings, compost, and leaf mold are better choices for retaining moisture, improving soil, and suppressing weeds, but they can smolder.
If you are using organic mulch for its many landscape and habitat benefits, keep it at least 5 feet from structures. Keep it moist through irrigation and consider replacing it over time with fire-resistant ground covers.
Inorganic mulches such as brick chips or decomposed granite are alternatives, depending on your goals. Another approach is to surround the mulch areas with a firebreak of gravel, rock or other landscaping material.
Fire resistant plants are not fire proof, but when properly cared for, they are less likely to ignite and more likely to survive a fire. They have a high moisture content and flexible leaves, and are generally drought tolerant, requiring less irrigation. They are easy to maintain and prune, often with an open and loose branching pattern. Their stems and leaves are not resinous, oily, or waxy.
Conversely, flammable plants accumulate dry or dead matter inside the plant. They contain waxes or volatile oils, often with aromatic leaves and resinous sap. Examples are ornamental junipers, Leyland cypress, Mugo pine, and shore pine. Noxious weeds Scotch broom and Himalayan blackberry are also flammable and should be removed, especially if they are near structures.
Many of the recommended plants are the preferred natives of the Pacific Northwest or North America. In addition to their fire resistance, most provide benefits for wildlife habitat and pollinators. Some examples:
Low-growing natives: Arctostaphylos uva-ursi (Kinnikinnick), Fragaria species (wild or beach strawberries), GaulthÃ©rie Shallon (salal), Mahonia repens (creeping grape from Oregon), Sedum spathulifolium (broadleaf stonecrop), Gaultheria procumbens (American wintergreen).
Perennials: Aquilegia formosa (western columbine), Echinacea purpurea (echinacea), Epilobium angustifolium (fireweed), Lonicera hispidula (pink honeysuckle).
Evergreen deciduous shrubs: Rhododendron macrophyllum (Pacific rhododendron), Ceanothus gloriosus (Point Reyes ceanothus).
Deciduous shrubs: Acer circinatum (vine maple), Holodiscus discolor (ocean spray), Philadelphus species (orange mock), Ribes species (flowering currant), Symphoricarpos albus (blueberry).
Trees: Acer macrophyllum (bigleaf maple), Populus tremuloides (trembling aspen), Quercus garryana (Oregon white oak, Garry oak).
There are many non-native fire-resistant plants, including varieties of iris, sage, lilac, delphinium, creeping thyme, mugwort, ice plant, and other succulents, and most deciduous hardwoods.
Find a research-based list of native and non-native fire-resistant plants on the East Jefferson Fire Rescue website: https://www.ejfr.org/wp-content/uploads/2020/04/FireResistantPlantsforHomeLandscapes.pdf.
Seabrook shared another important message: Despite our efforts to mitigate the risk, a wildfire can occur. ” Be ready. You may be in a situation where you have to evacuate at any time, so be prepared. “
The National Fire Protection Association is a good resource for advice on preparedness and planning: https://nfpa.org.
The master gardeners of the Online Plant Clinic organize weekly Live Zoom sessions on Mondays from 12:30 p.m. to 2:30 p.m. To book an appointment online or submit a written question, visit http://jefferson.wsu.edu/plant-clinic.
(Barbara Faurot is a Jefferson County master gardener and pruner, working with other volunteers who serve as community gardening and environmental stewardship educators.)