Those leaves that remain on the tree are usually covered with dark brown to black spots surrounded by reddish or purplish rings. The spots sometimes merge with others to form large, brown, dead areas on leaves. Soon afterwards, those leaves also may fall off. Although leaf spot is a definite threat to red tips growing in humid climates, there are some things that may prevent the fungus from ravaging your plants, according to James Blake, Extension plant pathologist and director of Clemson University's Plant Problem Clinic. Pruning or shearing during the growing season will encourage flushes of new growth which are highly susceptible to attack by Entomosporium.
Mature leaves are resistant to the fungus.
Remove infected twigs and leaves and rake up and discard fallen leaves. This reduces the amount of fungus present in the spring. If less fungus is present when growth begins, the amount of initial infection will be reduced. Above all, do not wet the leaves when watering. Water should be directed towards the base of the plant.