Napa County, CA Landscaping Rules: Tree Trimming (2026)

Chapter 8.36 of the Napa County Code (Fire Protection / Fire Hazard Abatement Ordinance) applies to all unincorporated areas of the county and to unincorporated areas within independent fire districts that have adopted enforcing resolutions. Section 8.36.060 declares as a public nuisance, requiring abatement by the property owner, any portion of a tree that extends within ten feet of the outlet of any chimney or stovepipe, the accumulation of dead or dying wood in any tree adjacent to or overhanging a structure, and the presence of prohibited materials (combustible vegetation, green waste, rubbish, or weeds) within the 100-foot defensible-space radius. The Napa County Defensible Space Guidelines (adopted by Resolution 2021- and updated May 2021) define a 0-5 foot Ember Resistant Zone using noncombustible landscaping materials, a buffer within 30 feet of any structure, and a Reduced Fuel Zone extending from 30 to 100 feet (or to the property line if less). The guidelines also identify pyrophytic species that should be avoided in the defensible-space area, including Coyote Brush, Manzanita, Chamise, Sagebrush, Scrub Oak, California Bay, Douglas Fir, Eucalyptus, Pampas Grass, Scotch Broom, French Broom, and various Junipers, Cypresses, and Pines. State law (California Public Resources Code Sec. 4291) parallels these requirements in State Responsibility Areas, requiring removal of tree portions within 10 feet of chimney outlets and keeping vegetation adjacent to or overhanging buildings free of dead or dying wood. Trees outside the defensible-space context are also regulated under the Water Quality and Tree Protection Ordinance and Conservation Regulations Chapter 18.108 (see Weed Ordinances entry).