Few serviceberry diseases are known since these shrubs are resistant to most garden pests and infections. However, due to a compact foliage and intense seasonal growth, serviceberry shrubs could develop seasonal vulnerability to some diseases. You should know how to identify and treat such serviceberry diseases.
This disease, commonly called "blight," is caused by the E. amylovora bacteria.
During the winters, fireblight causes canker development on the smaller, inner branches. During spring season, the cankers start rupturing and the infection spreads rapidly. Humid weather conditions, excessive irrigation and harsh pruning can cause faster spreading of blight. The blighted bark develops a moist appearance, as if water is oozing from the bark’s surface.
Fireblight is known to enter the plant through bruised plant tissue. In order to minimize shrub bruising, prune lightly. Decaying organic matter breeds blight development. You should remove weathered foliage from the garden bed. During the spring season, limit your pruning to the bare minimum. Always dip your pruning shears in a commercial fungicide. All infected branches should be pruned and burned. You should avoid using fertilizers with heavy nitrogen concentration, particularly during summers and the spring season.
Serviceberry Fungal Infection
A common fungal infection of serviceberry is the witches broom, which causes unwanted splitting of branches. The stems develop a clustered appearance with multiple split-ends among younger stems. This cluster of stem is the most prominent identifying feature.
Frequent spraying with all-purpose fungal sprays is effective. You should reduce the foliage density through light pruning. Isopropyl alcohol can be used for disinfecting shears used for pruning the infected shrubs.