Growing maple trees can be very rewarding, especially when they give back sweet syrup through maple tapping. They’re hardy, but like any living organism, they’re not immune to illness. If not properly cared for, they can become susceptible to pests and diseases.
If you’ve noticed your maple trees are looking a little under the weather or simply want to keep them thriving, this guide from Blain’s Farm & Fleet will walk you through common diseases and how to prevent them. With a little care and attention, you can ensure your trees stay strong year after year.
To care for your maple trees, it’s crucial to understand what might threaten their health. Below are some of the most common disease that affect maples, along with their symptoms and causes.
Tar spot is a fungal disease that affects the leaves of a maple tree. It’s easy to recognize by its distinct large, black spots on leaves, resembling drops of tar.
This infection begins in early spring and can continue into the summer, especially during prolonged wet weather when leaves are unable to dry off. It thrives in areas with high moisture levels, particularly when fallen leaves infected with fungal spores are left to decompose around the tree.
Fortunately, tar spot is mainly cosmetic and rarely harms the tree’s long-term health. The best way to prevent tar spot is to rake and dispose of fallen leaves around the tree. This will remove the fungus’ breeding ground.
Maple wilt, otherwise known as verticillium wilt, is one of the more serious maple tree diseases. Leaves will look scorched or slightly browned, often in patches. Branches may die back, and the wood beneath the bark can show dark streaks. This wilt can cause significant damage if left unchecked.
Maple wilt begins in the root system and spreads through the sapwood, moving up the tree and into the upper branches. Stressful conditions, such as drought or improper pruning, can make maples more susceptible.
While a very healthy tree can overcome maple wilt, most will die within one to two years of shown symptoms. If you suspect maple wilt, it’s a good idea to consult with your local county extension office. They can assist you in confirming if your tree is suffering from maple wilt.
If infestation is minor, pruning infected branches may help. But in severe cases, you’ll need to remove the tree to prevent the fungus from spreading to other trees.
Anthracnose is another fungal disease that affects the leaves of a maple tree. It will cause irregular purplish-brown or brown spots along the veins of the tree’s leaves and may result in stunted bud growth, early leaf loss, and even twig death. It’s most prominent after wet, cool winters and typically appears in April and May.
You can help to prevent anthracnose by raking up and removing fallen leaves where the fungus can thrive. For persistent outbreaks, you can consult with an arborist about a fungicide treatment.
Sapstreak is another fungal disease, which primarily affects sugar maples. It causes the foliage at the tree’s crown to shrink, resulting in stunted growth and eventually killing the tree.
Unfortunately, infected trees usually need to be removed promptly. Insects can spread the disease, so you’ll need to remove the tree to keep your other maples from becoming infected. Once the tree is removed, you’ll be able to see the recognizable sapstreak patterns in the cut wood.
Prevention is always better than cure when it comes to controlling maple tree diseases. The good news is you can prevent most of these issues with proper care and maintenance. Here are some practical steps you can take to protect your trees:
Maple trees are resilient, but like any living thing, they need attention to stay healthy. By staying vigilant and taking preventative steps, you can protect them from common diseases. With a little bit of care and effort, your maples will continue to thrive for years to come.
For more tips and how-tos, check out our other Trees articles.
