Norwalk, CA Invasive Plant Rules: Prohibited Species (2026)

020, the Water Efficient Landscape Ordinance, applies to new construction and rehabilitated landscape projects that trigger a landscape documentation package, generally rehabilitated areas of 2,500 square feet or more. Subsection B defines invasive plant species as species not historically found in California that spread outside cultivated areas and can damage environmental or economic resources, noting such species may be regulated by county agricultural agencies as noxious weeds and that lists are maintained at the California Invasive Plant Inventory and the USDA invasive and noxious weeds database.

Within the required landscape design plan standards in subsection E, applicants must select plants based on local climate suitability and horticultural attributes like invasive surface roots that could damage sidewalks or buildings, and subsection E(1)(f) directly addresses the topic: the use of invasive plant species, such as those listed by the California Invasive Plant Council, is strongly discouraged. That sits alongside related design mandates in the same subsection: turf is barred on slopes steeper than 25% next to hardscape, and high water use plants are flatly prohibited in street medians.

Because the discouragement language is advisory rather than a numeric prohibition, it functions as a design-review steer applied when the Department of Community Development reviews a landscape documentation package, rather than a standalone ban enforceable against existing yards planted before a project triggers this section.