Orange County, CA Landscaping Rules: Native Plants (2026)

There is no mandate forcing homeowners in unincorporated Orange County to plant native species. The relevant county rule is the Water Efficient Landscape Ordinance (WELO) Program, adopted March 14, 2016 and applied in the unincorporated area through OC Development Services. It enforces the state Model Water Efficient Landscape Ordinance (MWELO) by requiring water-efficient landscape and irrigation design on qualifying construction projects, steering plant selection toward low-water and climate-appropriate (often California-native) species and limiting high-water turf. Non-exempt projects must prepare and submit a project-specific Landscape Plan before a grading or building permit is issued, and the County references guidelines such as WUCOLS for estimating landscape water needs. Under statewide MWELO thresholds, the requirements generally attach to new landscapes of 500 square feet or more and rehabilitated landscapes of 2,500 square feet or more. For existing homeowners simply re-landscaping a yard below those thresholds, native and drought-tolerant plants are encouraged but not required. California Civil Code 4735 prevents homeowners associations from prohibiting low-water-using plants as a group or from blocking their use as a turf replacement, protecting residents who choose native, drought-tolerant landscaping.