Proving infringement has been difficult because so much has depended on coloration. However, today patent applicants are including the molecular biology of their plants, to make future identification in infringement cases easier to prove.

The infringers are people who take cuttings from original plants, perhaps bought legally at a nursery, and replicate them to their own benefit. For example, someone could buy one patented apple tree, take it back to his or her orchard, and breed acres of them over time, thereby robbing the inventor of royalties.