Yolo County, CA Landscaping Rules: Weed Ordinances (2026)

Yolo County's primary weed-management mechanism is cooperative rather than ordinance-driven. The Yolo County Weed Management Area, coordinated by the Yolo County Resource Conservation District, focuses on reducing infestations of designated noxious weeds (yellow star thistle, perennial pepperweed, and others) that threaten agriculture, wildlife habitat, and special-status species. Herbicide application is performed by certified RCD staff under an herbicide application permit issued by the County of Yolo Agricultural Commissioner, using best management practices to prevent spills and drift. The County Code does not prescribe a parcel-by-parcel grass-or-weed maximum height; rather, overgrowth that constitutes an actual hazard or nuisance is addressed under the County's general public-nuisance enforcement (Title 6 and Title 8 zoning violations are enforceable as public nuisances). For cannabis-permitted parcels, Title 8 (Cannabis Land Use Ordinance) requires that nonagricultural portions of the site 'be properly maintained through weed abatement and pest management to avoid maintenance deficiencies that impair or otherwise conflict with agriculture on nearby properties.' On wildland-adjacent parcels, California PRC Sec. 4291 supplies the substantive vegetation-clearance requirement (100 feet of defensible space). Within incorporated cities (Woodland, Davis, West Sacramento, Winters), city-level weed-abatement ordinances apply instead.