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

Siskiyou County does not have a stand-alone municipal "weed abatement" lien chapter of the kind seen in cities; instead, weed and brush control in the unincorporated area is driven by the fire-hazard code and by the state-mandated noxious-weed program. Under Siskiyou County Code Title 3, Chapter 3 (Fire Control and Fire Hazard Regulations), owners of buildings on mountainous, forest-, brush-, or grass-covered land must maintain firebreaks by removing all flammable vegetation or combustible growth for at least 30 feet around each structure (Section 3-3.02.1), with additional clearance from 30 to 100 feet (Section 3-3.02.2). It is also unlawful to store or accumulate flammable material so it becomes a fire hazard to adjacent property unless surrounded by an adequate firebreak (Section 3-3.03). Separately, weeds in the agricultural sense are addressed by the Siskiyou County Department of Agriculture, which operates one of the largest noxious-weed programs in the state to protect native species, crops, and forest land and to reduce fire hazard - using treatment and biocontrol against species like perennial pepperweed and leafy spurge. This is a control/eradication program, not a residential lawn rule. The statewide defensible-space duty of Public Resources Code 4291 reinforces the clearance of dry weeds and grass around homes in the State Responsibility Area.