Cal. Health & Safety Code § 14930

The board of supervisors may, by ordinance, compel the owner, lessee, or occupant of buildings, grounds, or lots in the county, to remove dirt, rubbish, weeds, or other rank growths from such property and adjacent sidewalks. If the owner, lessee, or occupant defaults, after notice prescribed by such ordinance, the board may authorize the removal or destruction of the dirt, rubbish, weeds, or rank growths at his expense by a county officer. The board may, by ordinance, prescribe a procedure for such removal or destruction and make the expense a lien upon the real property in accordance with Section 25845 of the Government Code.