Monterey County, CA Invasive Plant Rules: Prohibited Species (2026)

Section 16.63.070(B)(5), part of the Planting Plan requirements for major landscape projects, states that "invasive plants are strictly prohibited" in the landscape area and that eradicating any that are already present "is highly encouraged." The definitions section, § 16.63.020(W), defines an "Invasive plant" as a species not historically found in California that spreads outside cultivated areas and can damage environmental or economic resources, and that is listed in the California Invasive Plant Inventory maintained by the California Invasive Plant Council, the USDA invasive/noxious weeds database, or the county's Landscape Manual.

The prohibition applies to "major landscape projects," meaning those with an aggregate landscape area over 2,500 square feet under § 16.63.030(C), whenever new construction, new landscaping, or rehabilitation reaches that threshold tied to a grading permit, building permit, or design approval. Planting Plans must be prepared by a licensed architect, licensed contractor, or other person authorized to design a landscape (§ 16.63.070(B)(1)) and must instead favor native and native-compatible, drought-resistant, and fire-resistant species grouped by water need into hydrozones (§ 16.63.070(B)(6)-(10)). The Chief of Planning reviews compliance as part of the major landscape package under § 16.63.060(C).

Minor landscape projects at or under the 2,500-square-foot threshold are not required to submit a full Planting Plan and are not separately bound by this specific clause. The chapter applies only in unincorporated Monterey County, in coastal and non-coastal zoning districts alike.