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

Humboldt County Code section 351-3 defines a 'nuisance' to include 'any condition declared by any statute of the State of California or ordinance of the County of Humboldt to be a nuisance.' California Government Code section 25845 expressly authorizes county boards of supervisors to adopt ordinances abating nuisances on private property, and Gov. Code section 39561 (incorporated by reference for county-level analogues) treats 'all weeds growing upon the streets, sidewalks, or private property' as public nuisances. Under HCC section 351-8, the Code Enforcement Unit issues a Notice of Violation requiring the owner to commence correction within 10 calendar days. If the owner does not act, HCC section 351-5 allows summary abatement when the condition is an immediate threat, and HCC section 351-4 makes the owner liable for all 'enforcement, investigation and any other costs directly associated with the removal and/or correction of the condition.' Under HCC section 351-24, 45 calendar days after notice the county may record a Notice of Nuisance Abatement Assessment Lien with the County Clerk-Recorder. Separately, the County Agricultural Commissioner administers state noxious-weed regulations under California Food & Agric. Code section 5004, which defines noxious weeds as plants the director designates as 'troublesome, aggressive, intrusive, detrimental, or destructive to agriculture, silviculture, or important native species.'