Arcadia, CA Landscaping Rules: Native Plants (2026)

Native plants get their footing in the City's Water Efficient Landscaping ordinance, Sections 7554.1 through 7554.9. Section 7554.4.A.1.a says any plant may be selected for the landscape if the Estimated Total Water Use in the landscape area does not exceed the Maximum Applied Water Allowance. It then lists methods to reach that result, including protection and preservation of native species and natural vegetation and selection of water-conserving plant, tree and turf species, especially local native plants.

Other plant rules sit in the same section. High water use plants, with a plant factor of 0.7 to 1.0, are prohibited in street medians. Turf is not allowed on slopes greater than 25% where the toe of the slope is adjacent to an impermeable hardscape. Use of invasive plant species, such as those listed by the California Invasive Plant Council, is strongly discouraged, and plans for fire-prone areas must address fire safety and follow the local Fuel Modification Plan guidelines.

A common interest development cannot use its architectural guidelines to prohibit, or include conditions that have the effect of prohibiting, the use of low-water use plants as a group (Section 7554.4.A.1.h). Plant factor ranges are printed in Section 7554.4.D.3.a: 0.0 to 0.1 for very low water using plants, 0.1 to 0.3 for low, 0.4 to 0.6 for moderate and 0.7 to 1.0 for high. The water budget caps the ET adjustment factor at 0.55 for residential areas and 0.45 for non-residential areas, exclusive of Special Landscape Areas.

Mulch leaves room for habitat. Section 7554.4.A.3.d requires a minimum three inch layer of mulch on exposed soil of planting areas, but up to 5% of the landscape area can be left without mulch to provide habitat for beneficial insects and other wildlife, with the designated insect habitat identified in the landscape design plan.

Scope matters. Under Section 7554.3 the rules apply to new construction with an aggregate landscape area of 500 square feet or more and rehabilitated landscapes of 2,500 square feet or more, when a building or landscape permit, plan check or design review is required. Registered historical sites, ecological restoration projects that do not require a permanent irrigation system, mined-land reclamation projects without permanent irrigation, and existing plant collections in botanical gardens and arboretums open to the public are excluded. Model homes must use signs showing low water use approaches such as native plants.