San Mateo County, CA Landscaping Rules: Native Plants (2026)
Key Facts
- Homeowner mandate
- None - voluntary/incentivized
- Lawn replacement rebate
- Up to $4 per square foot
- Rain garden bonus
- $300
- WELO plant factor
- WUCOLS 0.3 favors natives
- Program
- Flows To Bay / BAWSCA / Office of Sustainability
Summary
Unincorporated San Mateo County encourages native and drought-tolerant landscaping rather than mandating it for homeowners. The Countywide Water Pollution Prevention Program promotes natives for pollinators and watershed health, and BAWSCA's Lawn Be Gone rebate pays up to $4 per square foot to replace lawn with low-water plants. WELO indirectly favors natives through plant-factor rules.
About 40% of the water Californians use at home is used outdoors. Large water savings can be gained by efficient landscape design, installation, management, and maintenance. This is accomplished by choosing climate adapted plants, improving soil conditions, using, and maintaining high efficiency irrigation equipment and managing the irrigation schedule to fit the plants water needs as they are influenced by local climate. To increase water efficiency and better use a valuable resource, rainwater and stormwater collection and graywater and recycled water can replace or augment potable water use in landscapes. New development and retrofitted landscape water efficiency standards are governed by the Model Water Efficient Landscape Ordinance (MWELO) . The MWELO is also referenced by Title 24, Part 11, Chapters 4 and 5 CalGreen Building Code. All local agencies must adopt, implement, and enforce the MWELO or a local Water Efficient Landscape Ordinance (WELO) that is at least as effective as the MWELO. Usually, local agencies that adopt WELOs create a more stringent ordinance than MWELO.
Official source re-checked September 8, 2026: the cited page had not changed since it was quoted.
Full Breakdown
3 - a standard easily met by California natives. The San Mateo Countywide Water Pollution Prevention Program (Flows To Bay) highlights native plants for water conservation, reduced pesticide use, low maintenance, and pollinator support, noting that monarch butterflies depend on native milkweed and recommending species such as purple needlegrass, hummingbird sage, coyote mint, and miniature lupine (with selection tools like CalScape). Financial incentives reinforce the message: BAWSCA's Lawn Be Gone (lawn replacement) rebate pays up to $4 per square foot to convert turf to drought-tolerant plantings, with an additional $300 rebate for adding a rain garden.
These are voluntary, rebate-driven programs administered with water agencies and the County Office of Sustainability, plus free landscaping classes through BAWSCA and UC Master Gardeners. Note that native plantings still interact with defensible space and tree rules - removing protected native oaks or madrones to landscape still requires a tree permit (see Tree Removal).
Violations & Fines
Native-plant programs are incentive-based with no penalties for non-participation. However, removing protected native trees (oaks, madrone, buckeye) to install a native garden without a tree permit, or violating WELO plant-factor requirements on a regulated project, can trigger enforcement under those separate ordinances.
Frequently Asked Questions
Am I required to plant native plants in unincorporated San Mateo County?
Is there money to replace my lawn with natives?
Sources & Official References
Other rules in San Mateo County
California rules heatmap·Compare San Mateo County to another location·View the California landscaping rules overview
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