When a cherry tree looks sick, a wise gardener wastes no time in trying to figure out what is wrong. Many cherry tree diseases get worse if untreated, and some can even prove lethal. Fortunately, it usually isn’t too hard to diagnose the problem. The common cherry tree diseases have recognizable symptoms. Read on to learn more about cherry tree problems and the best methods of treating diseases of cherry trees.
Cherry Tree Problems
Common cherry tree problems include rot, spot and knot diseases. Trees can also get blight, canker and powdery mildew.
Root and crown rot diseases result from a fungus-like organism that is present in most soils. It only infects the tree if the moisture level of the soil is very high, like when the tree grows in standing water.
Symptoms of rot diseases include slowed growth, discolored leaves that wilt quickly in hot weather, dieback and sudden plant death.
This is one of the worst cherry tree diseases. Once a cherry tree has a rot disease, there is no cure. However, rot diseases of cherry trees can generally be prevented by making sure the soil drains well and regulating irrigation.
Treating Cherry Diseases
Treatment is available for most other common cherry tree diseases, like black knot fungus. Recognize black knot by the dark, hard swellings on branches and twigs. The galls grow each year, and branches may die back. Treat it early by cutting off an infected branch at a point below the gall, and applying fungicides three times annually: in spring, just before flowering and just after.
Fungicide application is also the treatment of choice for brown rot and leaf spot. Shriveled fruit covered with spores indicates brown rot, while purple or brown circles on leaves signal Coccomyces leaf spot.
For brown rot, apply the fungicide when buds emerge and again when the tree is 90 percent in bloom. For leaf spot, apply as leaves emerge in spring.
Other Diseases of Cherry Trees
If your cherry tree suffers drought stress or freeze damage, it may come down with Leucostoma canker. Recognize it by the cankers that often ooze sap. Prune off these limbs at least 4 inches (10 cm.) below the diseased wood.
Coryneum blight, or shot hole, causes dark spots on emerging leaves and young twigs. If cherry fruit is infected, it develops reddish bumps. Prune away all diseased parts of the tree. This disease can often be prevented by taking care not to let irrigation water touch the tree leaves. For severe infections, apply copper spray at 50 percent leaf drop.