text: I have lived and worked in the garden center field in New York, Pennsylvania, Connecticut and Rhode Island and in all four states you needed a license from the state.  It usually comes from the Department of Agriculture.  We brought plant material in from California and I'm pretty sure we had to have the nurseries license number or a copy on file for our records.  I am sure you need a license to sell plant goods in California, check with your Dept. of Agriculture.