Diseases of the Flowering Cherry Tree

Flowering cherry trees burst into bloom in the spring with a mass of white, pale pink or dark pink flowers. The fruits are not ornamental but they are a good food source for birds. Varieties differ in form--upright, pyramidal, round, and even weeping. Plant flowering cherry trees in a group, or as specimen or accent plants in full sun and well drained soil.

Sooty Mold

Sooty mold is a fungus that that forms a black coating on leaves, fruit, twigs and branches of flowering cherry trees. The spores of the fungus grow on honeydew,a sweet clear sticky substance secreted by aphids, mealybugs, scale insects and whiteflies.

Spray trees with an insecticide approved for aphids, mealybugs, scale insects and whiteflies on flowering cherry trees, according to the manufacturer's directions. Wash the sooty mold off trees with water.

Powdery Mildew

Powdery mildew causes dusty white or gray patches on the leaves of flowering cherries. As it spreads, powdery mildew stunts and distorts the growth of leaves, buds and growing tips. Infected flowering cherries will decline and lose vigor if left untreated.

High humidity, too much shade, and trees planted too close together are some factors that encourage the growth of powdery mildew. Remove fallen leaves, buds and other debris from around trees. Apply a fungicidal spay approved for powdery mildew on flowering cherries at the rate recommended by the manufacturer.

Brown Rot

A fungus causes brown rot on flowering cherry trees. Flower buds turn brown and die before they fully open. The buds remain on the tree and develop a grayish-brown fungal growth. The fungus spreads to the shoots and stems of the tree.

Prune infected plant parts out of trees. Clean fallen leaves and other debris from around trees. Avoid fertilizer with a high nitrogen content, which increases the susceptibility of flowering cherry trees to brown rot. Use a fungicidal spray, if desired. Choose one approved for brown rot on flowering cherry trees and apply following manufacturer's directions.

Bacterial Canker

The buds do not open on flowering cherry trees infected with bacterial canker. Small greasy-looking spots appear on new leaves, followed by shots holes where infected leaf material falls out. The holes spread causing the death of shoots and cankers on branches.

Prune infected plant parts out of trees. Spray with a copper-based spray approved for use on flowering cherry trees at the rate recommended by the manufacturer. Allow adequate space between trees, based on mature tree size, to minimize the risk of diseases.