Los Angeles County, CA Invasive Plant Rules: Prohibited Species (2026)
Key Facts
- Authority
- Ag Commissioner
- State Law
- CA Food & Ag Code §5004
- Noxious Weeds
- Giant reed, pampas grass
- Water Ordinance
- Title 22 §22.52.2200
Summary
The LA County Agricultural Commissioner maintains a list of noxious weeds and invasive plant species. California's noxious weed list (Food & Agriculture Code §5004) applies countywide. Additionally, the county's landscaping and water-efficient ordinance discourages high-water-use ornamental species.
5004. 'Noxious weed' means any species of plant that is, or is liable to be, troublesome, aggressive, intrusive, detrimental, or destructive to agriculture, silviculture, or important native species, and difficult to control or eradicate, which the director, by regulation, designates to be a noxious weed. In determining whether or not a species shall be designated a noxious weed for the purposes of protecting silviculture or important native plant species, the director shall not make that designation if the designation will be detrimental to agriculture.
Full Breakdown
The LA County Agricultural Commissioner/Weights and Measures department enforces California Food and Agriculture Code provisions regarding noxious weeds. State-listed noxious weeds (such as giant reed/Arundo donax, pampas grass/Cortaderia spp., and yellow starthistle) are subject to eradication or containment orders. The county runs active eradication programs for species like the Asian citrus psyllid and Huanglongbing disease. Under LA County's Water Efficient Landscape Ordinance (Title 22, Chapter 22.52.2200), new landscaping projects over 500 square feet must comply with the State Model Water Efficient Landscape Ordinance (MWELO), which discourages high-water-use turf and encourages drought-tolerant, native plantings. The California Invasive Plant Council (Cal-IPC) maintains a comprehensive inventory of invasive plants relevant to LA County ecosystems.
Violations & Fines
Failure to control state-listed noxious weeds after notice may result in county-performed abatement with costs charged to the property owner. MWELO landscape violations can delay project approvals.
Frequently Asked Questions
What plants are prohibited in LA County?
Does LA County regulate landscaping water use?
Sources & Official References
Other rules in Los Angeles County
California rules heatmap·Compare Los Angeles County to another location·View the California invasive plant rules overview
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