According to the Plumeria Society of America, Inc., plumeria requires minimal pruning that is best done during spring before the growth of new leaves. Pruning allows the tree to produce symmetrical branches that leads to a compact, bush-like shape. Left unpruned, plumeria tends to develop a lanky, loose form.
Plumerias are pruned for certain reasons. Pruning helps to keep the tree to desired height and spread. While pruning, take care to remove all diseased or damaged branches or tips. Often there are long sections of branches that are no longer branching. Also remove these during the pruning. These branches may be used as cuttings for propagating new plants. When cutting these branches, make the cut about a foot below the branching point.
When plumeria is stored over the winter, branch tips are prone to develop a disease called black tip rot. This can spread to other plant areas and other plants in the landscape if not removed in time. Branches that are frost damaged also need removal in spring. Inspect branches for pest infestation from the longhorn borer or other grub like worms. Remove these branches during pruning. Use sterilized pruning equipment when removing diseased branches. Make all cuts at the clean white, non-diseased areas. Discard diseased wood carefully to prevent spread of disease.
Healthy branches easily propagate into new plants. Place the cut branches in a warm, dry area and let it dry for about a week. Dip the cut end into a rooting hormone and plant in a medium sized pot filled with a good quality potting soil or equal amounts of sand and perlite. Place pot in an area of full sun and water enough to keep the soil moist. It usually takes 6 to 8 weeks for the cutting to root and new growth to appear.