Cal. Food & Agric. Code § 6724

There shall be four licensing periods as follows: January through December, April through March, July through June, and October through September. The fees for the renewal of the license for the foregoing periods shall be paid by the 1st day of the first month of the licensee’s license period. If the renewal license fee is not paid prior to the 11th day of the first month of the licensee’s license period, for the 12-month period ensuing, the license to sell nursery stock is forfeited.