Firewise Landscaping

FireWise landscaping can be aesthetically pleasing while reducing potential wildfire fuel. Critical to creating a fire-resistant landscape is plant choice, spacing and maintenance, but remember no plant is fireproof, all plants will burn in a very intense fire.

Plant Choices:  Planting native plants are good choices for creating natural habitats for wildlife and supporting pollinators, but not all native plants are Firewise plants. Prior to purchasing, know a plant’s growing requirements, habits  and fire rating.  Also be aware that a native plant may not be well adapted for your area, for example an Oregon native plant which grows in wetter NW Oregon, may not thrive in drier parts of Oregon, like Southern or Eastern Oregon.  Therefore, it’s important to research all plants prior to buying. Also, only buy plants rated for your hardiness zone.

Firewise plants all have one or more of these characteristics:

  • Tissues contain more moisture, especially during the fire season.
  • Tissues contain low amounts of volatile oils and other readily flammable chemicals.
  • Plants provide less fuel, either by producing less litter or by staying small.
  • Plants are compact or low to the ground, so they can be used in the landscape to interrupt fire pathways.

Deciduous plants tend to be more fire resistant because their leaves have higher moisture content and are less flammable.  Avoid plants that shed leaves or needles during droughts. Drought-tolerant species with smaller leaves, or succulent leaves, have higher moisture content which helps reduce fire hazard.  Annuals can be in your firewise landscape too, if you keep them well watered and maintained.

Plant Spacing: Choose healthy plants for your hardiness zone.  Plant firewise vegetation, and other flora, in well-spaced groupings, and plant according to their label’s instructions; don’t overcrowd them!  They might be small now, but it is imperative to space them in the ground as if they are grown!  Pick plants that have low maintenance and use minimal water, especially during the dry season. Plant only firewise approved vegetation within 5 feet of your house and out buildings; then keep them low and compact. Trees 30 to 60 feet from the home should have at least 12 feet between canopies. Check Idaho’s Firewise Plant Database charts for placing plants by “Firewise Landscape Zones”. Irrigation should be available within 30 feet of your home.

Plant Maintenance: After planting Firewise plants, they must be maintained to retain their FireWise properties. This means removing dead leaves and stems, and removing dry litter around and under plants. Prune trees to keep crowns clean of dead branches and limb tree branches 6-10 feet (depends on their height) above the ground and above structures.  Keep plants thinned out to break up a fire’s fuel sources and remove weeds and tall grasses that can dry out and be ignited. Remove highly volatile plants close and around your home and outbuildings.

Create a defensible space around your house. A defensible space is defined as “an area around a building in which vegetation, debris, and other types of combustible fuels have been treated, cleared, or reduced to slow the spread of fire to and from the building.  Wildland vegetation such as grass, brush, and timber can be extremely combustible.” Firewise.org

Article by: Carlotta Lucas, AGC Board Member

Firewise Resources:

Oregon State University  https://www.firefree.org/wp-content/uploads/2016/02/Fire-Resistant-Plants.pdf

Idaho’s Firewise Plant Database: http://idahofirewise.org/FirewiseLandscaping.pdf

FireFree: https://www.firefree.org/fireresistantplants/

NFPA: https://www.nfpa.org/Public-Education/Fire-causes-and-risks/Wildfire/Preparing-homes-for-wildfire

USDA Hardiness Map: https://planthardiness.ars.usda.gov/PHZMWeb/