Any individual within California that sells plants for planting, propagation, or ornamentation is required to have a nursery stock license. A general standard of cleanliness shall be maintained for all nursery stock. Nursery stock should be commercially clean in respect to established pests of general distribution; pests can only be present to a light degree. All nursery stock shall be kept free of pests of limited distribution, of major economic importance, and pests not know to be established in the state. In addition, conditions in and around the nursery should not create the potential to expose nursery stock to infestation, including weed seed.