Riverside, CA Landscaping Rules: Weed Ordinances (2026)

Riverside's weed-abatement program is mandated by California Government Code sections 39501–39588 and implemented locally through the Fire Code and property-maintenance ordinance. Each spring, the Fire Marshal sends notices to owners of parcels identified with excessive weed growth or dry vegetation. Owners typically have 30 days to abate — meaning to disc, mow, or clear vegetation to a height not exceeding three to six inches depending on zone. Combustible debris, tumbleweeds (Salsola tragus), and accumulated cuttings must be removed from the site. Parcels in the VHFHSZ (hillside areas mapped by CAL FIRE) face stricter 100-foot defensible-space obligations under Public Resources Code section 4291. Owners who fail to abate face City-contracted abatement performed by a licensed contractor, with costs (often $500 to $2,500 per parcel) plus a 25 percent administrative fee placed as a tax-roll lien. Ragweed, star thistle, poison oak, and other noxious weeds listed by the California Department of Food and Agriculture may receive priority enforcement. Pre-emergent herbicide application is allowed but must not contaminate storm drains that feed the Santa Ana River. Residents may report overgrown neighboring parcels through the City's RiversideConnect app or Code Enforcement at (951) 826-5633.