Apple trees are very productive species and it’s easy to find cultivars for all sorts of taste and color preferences and climates. Despite the fact that they are easy to grow, there are a number of diseases and pests that the species is prone to. If you want to avoid such problems through the years, it’s best to look for disease-resistant cultivars, especially the ones that resist the problems that have prevailed in your garden over the growing seasons in the past.
If you want to learn why your apple tree branches are dying back, you’re at the right spot. Continue reading and you’ll understand all the possible causes that could lead to this symptom, together with some expert advice on how to resolve the issue.
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Fire blight is a serious bacterial disease that’s prevalent in many regions and can cause the branches to die back. The leaves, blossoms and branches on the infected portions of the tree appear scorched and brown. Open cankers may ooze out viscous bacterial fluid from time to time. The disease usually hits the tree in the winter months and spreads quickly as the weather warms up in spring.
Fuji and Gala apple trees are particularly prone to the problem, while William’s Pride and Jonafree are some of the more resistant cultivars. Prune out the infected branches in the winter months when the tree is dormant. Currently, there are no sprays that can completely eliminate fire blight from the infected trees.
If the dieback of branches is accompanied by sunken and dead areas on the bark of the apple tree, it’s most likely apple cankers that you are dealing with. The disease can affect the shoots, branches and even the main trunk of the tree. New cankers form around mid spring and once they appear, they’ll remain in place throughout the year.
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Cankers are more damaging to the tree if the soil is heavy, wet or acidic. Make sure the soil drains well. If the soil is acidic, you can raise the pH by liming it. Prune out and discard the infected branches by cutting as far as fresh green tissue. Paint the open cuts immediately with protective wound paint. Resistant cultivars include Alfriston, Annie Elizabeth, Newton Wonder and Winston.
Silver leaf disease is a fungal disease that infects the leaves and wood on the apple tree. The fungus infects the tree through open wounds and initially causes the silvering of the leaves before the branches start to die back. You’ll find bracket shaped fruiting bodies on old dead branches with whitish soft upper surface and purplish brown surface underneath.
Prune out the infected branches before fruiting bodies form since that’s where the spores will spread from. Disinfect the pruning material and discard the pruned branches safely so that they don’t spread the spores elsewhere.
Coral spot is a fungal disease that doesn’t only attack apple trees but a wide variety of woody plants, causing the branches to die back. If the dead branches are accompanied by coral-pink pin-sized spots called pustules, you’re most likely dealing with coral spot.
Apple trees that are weakened or are dying due to other diseases or pests are the ones that are most susceptible to a coral spot infection. Prevention involves planting hardy cultivars and avoiding pests, diseases and weeds. Only prune the infected branches when the weather is dry, cutting off the branches at the collar since that’s where they will heal the fastest.
Apple tree root rot, or Phytophthora collar rot, or crown rot or collar rot is caused by the plant pathogen Phytophthora cactorum. Dwarf rootstocks and apple trees growing on poorly draining soil are the most susceptible to this disease. Symptoms appear around spring time and are shown as discolored leaves, delayed bud break and dying back of branches. The infected trees decline slowly, over a span of years which eventually results in death of the entire tree. Cool temperatures and rainfall triggers the spread of fungal spores.
Through root rot, collar rot and crown rot are all the different names for the infection caused by the same fungus, they refer to different regions of the tree where the infection hits. Root rot refers to the infection in the roots, while crown rot occurs when the lower part of the trunk and the roots at the base of the tree are infected. Collar rot occurs when the same infection hits the tree above the tree union.
Once the infection occurs, it’s difficult to control. Preventive measures involve avoiding dwarf rootstocks and growing resistant varieties, including Lodi, Golden Delicious, Red Delicious, and Winesap.
Blossom wilt is another fungal disease that causes similar symptoms, i.e. dying back of branches. However, the dying back of branches that results from blossom wilt is slightly different than that caused by other problems. In blossom wilt, several shoots die back late in spring after flowering. The leaves shrivel up and turn brown but the dead part of the shoot rarely extends more than 1 foot.
Prune out and burn the infected branches, blossoms and fruit to prevent the fungal spores from spreading. There are no fungicides available currently that are known to control blossom wilt. To prevent the disease from occuring in the first place, you can choose resistant cultivars, such as Bramley. Avoid growing James Grieve, Lord Derby and Cox since they’re very susceptible to the disease.
So there are many possible reasons why the apple tree branches may be dying back. Don’t take the symptom lightly as the problem that’s causing the branches to die back can progress further and take hold of the tree if action isn’t taken promptly.