Sonoma County, CA Landscaping Rules: Tree Removal & Heritage Trees (2026)

Sonoma County's Tree Protection Ordinance (County Code Section 26-88-010(m)) protects roughly 31 native species, including all native oaks, willows, alders, cottonwoods, maples, ash, madrone, buckeye, walnuts, firs, redwoods, cypress, and pines, once they reach 6 inches diameter at breast height (DBH). Removing such a protected tree generally requires a zoning permit; removing a hardwood 36 inches DBH or larger or a redwood 48 inches DBH or larger requires a more demanding discretionary use permit (some species such as Western hemlock, Monterey/Macnab cypress, and pines have no use-permit size threshold). The County updated its tree ordinances in 2024 - the Board of Supervisors adopted updated Tree Protection and Oak Woodland ordinances on April 16, 2024, the first comprehensive update since 1989 - increasing protections and penalties. Mitigation is required for most removals: the published in-lieu fee is $510 per single arboreal value point, where a 6-inch tree equals one point and larger trees accumulate more points by diameter (e.g., a 36-inch redwood equals six points, about $3,060). Application forms include PJR-151/PJR-153 for zoning permits and PJR-150/PJR-152 for use permits. Note that valley oaks within a Valley Oak Habitat Combining Zone are regulated separately and more strictly (see the dedicated tree-protection topic).