They open and release spores, which then re-settle on other frangipani trees, spreading the disease. Severe rust infections, particularly in young plants, may cause the leaves to drop prematurely and even lead to the death of the plant. Badly affected leaves shrivel up, turn brown and die.Click to see full answer. Also to know is, how do you revive a frangipani tree?Don’t cut back you frangipani tree – it will recover! What you can do though is to remove the affected leaves and place these in a bag and put them in the bin. Don’t compost them, and don’t let the leaves fall onto the soil as this will just spread the fungus spores which cause the rust. how often do you water a frangipani tree? Water During dry summers, water newly planted trees at least once or twice a week, when the soil feels dry to touch. Once established, they’re fairly drought tolerant and rely mostly on watering from rainfall, although a drink once in a while will help them along. Correspondingly, what’s wrong with my frangipani? Frangipani can be susceptible to fungal diseases, such as downy and powdery mildew and frangipani rust, which can all be treated. Stem rot and black tip die back, as the names suggest, result in rotting stems and tip growth blackening and dying.Why is my frangipani dropping leaves?Water is especially important during the hot, summer months, when insufficient water may cause the plant to drop leaves and go into dormancy at the wrong time of year. If the plumeria’s leaves start to fall and its buds stop enlarging during the growing season, then underwatering may be the problem.