Plumeria cultivators maintain the purity of a cultivar by ensuring that it does not cross-pollinate with other Plumeria plants. When hybridizing or creating new cultivars, breeders take steps to prevent pollen from different plants from reaching the target cultivar’s flowers. They may use isolation techniques, such as bagging the flowers or utilizing greenhouses to prevent unwanted pollen transfer. By carefully controlling pollination, breeders can preserve the genetic purity and unique traits of a specific cultivar, ensuring that its offspring closely resemble the parent plant and maintain its valuable characteristics.