Plumeria flowers are most fragrant at night in order to lure sphinx moths to pollinate them. The flowers yield no nectar, however, and simply trick their pollinators. The moths inadvertently pollinate them by transferring pollen from flower to flower in their fruitless search for nectar. Insects or human pollination can help create new varieties of plumeria.
Plumeria trees from cross-pollinated seeds may show characteristics of the mother tree or their flowers might just have a totally new look. Plumeria species may be propagated easily by cutting leafless stem tips in spring. Cuttings are allowed to dry at the base before planting in well-drained soil. Cuttings are particularly susceptible to rot in moist soil. One optional method to root cuttings is applying rooting hormone to the clean fresh-cut end to enable callusing.
Plumeria cuttings could also be propagated by grafting a cutting to an already rooted system. The Plumeria Society of America lists 368 registered cultivars of Plumeria as of 2009.