California Code, Food and Agricultural Code (Formerly Agricultural Code) - FAC § 23

(a) Inasmuch as the planned production of trees, vines, rose bushes, ornamental plants, floricultural crops, and other horticultural crops is distinguishable from the production of other products of the soil only in relation to the time elapsing before maturity, plants and floricultural crops that are being produced by nurseries, whether in open fields or in greenhouses, shall be considered to be “growing agricultural crops” for the purpose of any laws that pertain to the agricultural industry of the state, and those laws shall apply equally to greenhouses and open field nursery operations.

(b) For the reasons stated in subdivision (a), a nursery where the primary activity is the planned production of horticultural crops, is a farm. However, for the purposes of this section and any laws that pertain to farms in this state, a retail nursery is not a farm.