The large size and wonderful flavor of the bing cherry tree's fruit make it one of the most popular sweet cherry varieties. And home gardeners love it because it is fairly easy to cultivate. However, while hardy, the bing cherry tree is susceptible to a few diseases. To keep your bing cherry healthy, monitor it frequently to spot symptoms as early as possible.
Bacterial canker causes cankers or swollen areas to form on the trunk, limb and branches of the bing cherry tree. The leaves develop dark brown leaf spots that may or may not be surrounded by a yellow ring. The fruit develops water soaked spots that eventually become blackened and depressed and the twigs develop elliptical lesions and may become girdled causing leaf, flower or fruit drop. To control bacterial canker, prune all affected foliage.
A virulent fungal disease, black knot causes wart-like protrusions to develop on new shoots, twigs or branches. When the knots first emerge, they are olive green but turn hard and brittle over time. These growths can be anywhere from 1 inch to 1 foot in size. To control black knot, prune the knot and then spray the tree with a fungicide prescribed for black knot.
When a bing cherry is affected with brown rot, its fruit may develop small red halos or large rotting pitted areas. Remove all of the affected fruit to stop the spread of infection.