Wildfire Mitigation
Defensible Space Zones Explained (and How Oregon's Approach Differs from California's)
Defensible space works in bands around a home, with the most aggressive fuel reduction closest to the structure. Fire scientists call this the home ignition zone. Understanding the zones helps property owners around Salem and the Mid-Willamette Valley prioritize the work that protects a house most. One caution up front: Oregon does not use California's exact zone distances, and confusing the two leads people to apply the wrong standard.
Defensible space works in concentric zones around your home
Defensible space is managed in concentric bands, treated most intensively next to the structure and less so farther out. Fire reaches a home two ways: as flames traveling through continuous vegetation, and as wind-driven embers landing on or near the house. The zone approach interrupts both. Each band has a different job, and the work eases as distance from the structure grows. Embers that land on the house itself are handled by home hardening for wildfire.
The five-foot noncombustible zone is the highest priority
The first five feet around a home is the single most important band, because embers are the leading cause of home ignition during wildfires. Research from the Insurance Institute for Business and Home Safety drove Oregon’s focus on this zone, and the State Fire Marshal launched a public campaign in 2026 built around it. The goal here is simple: give embers nothing to catch.
Use noncombustible ground cover. Replace bark mulch with gravel, pavers, or bare soil in the first five feet.
Move combustibles away. Relocate firewood, lumber, and stored materials out of this band.
Strip dead material. Remove leaves and needles from the roof, gutters, and the ground next to the wall.
Address touching fences. A combustible fence attached to the house carries fire straight to it.
The intermediate zone runs roughly 5 to 30 feet out
The intermediate zone reduces how fast and how intensely fire moves toward the house. Work here focuses on breaking up fuel so flames cannot run unbroken across the yard. Remove dead grass, weeds, and cured brush. Space shrubs and trees so their canopies do not touch. Remove ladder fuels, the low limbs and brush that let a ground fire climb into tree crowns.
The extended zone runs roughly 30 to 100 feet out
The extended zone lowers the overall fuel load so a fire arrives at the inner zones with less energy. This band does not need to be bare. Thin dense stands of trees, remove small conifers growing between mature trees, dispose of heavy ground litter, and space tree canopies apart. On larger Mid-Valley acreage, this is often where blackberry thickets, brush, and neglected undergrowth accumulate most.
Does Oregon use the same zones as California?
No. The fixed 0-to-5, 5-to-30, and 30-to-100 foot zones are California’s framework, set by CAL FIRE under state law. Oregon’s finalized model code centers the five-foot noncombustible zone and sets perimeter distances by local hazard determination rather than by three fixed national bands. The concentric logic is the same, and the distances above are useful planning references, but the legal specifics in Oregon come from whatever code your local jurisdiction has adopted. Verify the standard that applies to your property locally.
Fire-resistant plants belong in the outer zones
Plant choice inside the intermediate and extended zones shapes how a landscape behaves under fire. Oregon’s model code references the Pacific Northwest guide to fire-resistant plants, publication PNW 590, as its standard for species selection. Fire-resistant plants share traits that slow ignition: high moisture content in the leaves, low resin or oil content, and an open growth habit that does not accumulate dead material. Examples suited to Willamette Valley yards include many maples, currants, and native shrubs with high leaf moisture.
No plant is fireproof, and the label describes relative resistance rather than immunity. Placement matters as much as species: even a resistant plant stacked against a wall or left to collect dead litter becomes a hazard. Spacing, irrigation, and dead-material removal turn a plant list into a working defensible space.
Bring your property’s zones up to standard
Noosh handles the heavy work in the intermediate and extended zones for properties across Salem, Keizer, and the Marion and Polk county areas. Our crews thin brush, remove ladder fuels, and space vegetation to slow a fire‘s approach. Request a wildfire mitigation estimate today.
Frequently Asked Questions
What is Zone 0 or the ember-resistant zone?
Zone 0, also called the ember-resistant or noncombustible zone, is the first five feet around a structure. It matters most because wind-driven embers, not direct flames, ignite the majority of homes lost to wildfire. Keeping this band free of combustible material removes the fuel embers need.
Can I have plants in my defensible space?
Yes. Defensible space does not mean a ring of bare dirt. Properly spaced, irrigated, low-growing plants are acceptable in the intermediate and extended zones. The priority is spacing and fire-resistant species, not removing all vegetation.
Is zone distance measured from the wall or the property line?
Zone distance is measured outward from the exterior wall of the structure, including attached decks. Defensible space extends to the property line or the zone distance, whichever comes first. You are not required to treat land you do not own.
Do slopes change the distances?
Yes. Fire moves faster uphill, so properties on slopes often need greater setback distance and wider spacing on the downhill side. Steeper ground raises fire intensity, which is why local determinations account for slope.
Need help with wildfire mitigation?
Noosh Stump Removal handles wildfire mitigation across Salem and the Mid-Willamette Valley. See our wildfire mitigation service or get an estimate for your property.