How Do You Know If Your Tree Has Anthracnose?

It's important to keep an eye on the trees in your yard to make sure that they're not showing any symptoms of disease. One disease that can affect your trees is anthracnose, which is caused by a fungal infection. It affects several species of common shade trees—like oak, maple, and ash—and it interferes with new growth. 

Thankfully, anthracnose rarely kills established, mature trees. The fungal infection primarily affects new leaves and branches, leaving the mature ones unharmed. If you notice signs of anthracnose in a young tree or one that's stressed because of over-pruning, however, it's important to take quick action to try to save it. To learn how you can spot anthracnose in your trees, read on.

New Leaf Growth Is Brown and Curled

The fungus that causes anthracnose starts spreading spores in the spring, which is why it mostly affects new growth. When your tree has anthracnose, its newly grown leaves will appear brown and curled at the edges. You'll notice this mostly on the lower branches of the tree which aren't yet well-established, making them more prone to being affected by the fungus.

Your Tree Sheds Its New Growth

If your tree has a severe case of anthracnose, it will shed all of the new leaves it tried to grow on its lower branches during the spring. In a severe infection, the fungus will spread into the leafstalk connected to the newly grown leaf. This will kill it and cut off the nutrient supply that the leaf needs to grow. Once the leaf dies from a lack of nutrients, it will fall off.

Fresh Twigs and Petioles on Your Tree Develop Blisters

If the fungus is spreading from the leaves further into your tree, it will cause the twigs and petioles to form orange or brown blisters. Petioles are the tiny stems that connect a leaf to the branch it originated from. You may also notice that the twig or petiole that has a blister growing on it feels mushy to the touch.

If you notice any signs of anthracnose in your trees, call a tree diagnosis service for an evaluation. While anthracnose typically only affects new growth, it's important to have a professional examine the health of your tree. Young trees or trees that are stressed due to drought or over-pruning may lose too many leaves as a result of the infection, which can endanger their health. Trees use leaves to create energy via photosynthesis, and they can die if they're losing all their new growth because of anthracnose. A tree diagnosis service can determine if your tree has anthracnose and estimate the risk that the infection poses to your tree based on its health.

Contact a local tree diagnosis service to learn more.