Riverside County, CA Landscaping Rules: Grass Height Limits (2026)

Unlike many cities, unincorporated Riverside County does not publish a single maximum height (such as 6 or 12 inches) for an ornamental front lawn. The controlling rules are fire-safety driven and enforced by the Riverside County Fire Department Hazard Reduction office under County Ordinances 695 and 772. The County conducts field inspections of unimproved lands and adjacent vacant parcels to identify hazardous vegetation, dry grass, dead plants, brush, and other flammable material that threaten structures, roadways, and the public. Where vegetation poses a fire hazard, property owners receive a Notice of Violation and Order to Abate stating the method and amount of clearance required. Clearance is generally limited to what is necessary to establish defensible space, up to 100 feet from structures on the parcel or adjoining properties. California state law (Public Resources Code 4291) reinforces this by requiring 100 feet of defensible space around buildings in fire-hazard areas, and CAL FIRE guidance calls for cutting annual grasses to a maximum height of about four inches. So while a homeowner's watered lawn is not measured by the inch, dry grass and weeds that create fire risk must be mowed, disced, or cleared. Property owners have 30 days from the Notice to comply before the County may abate at the owner's expense.