The sight of brown or black spots on the leaves of your trees is definitely a cause for concern because they often indicate that there's an underlying health issue that needs to be addressed. It can be difficult, however, to pin down exactly what's causing the problem. Here are five possibilities.
1. Fungal Disease
There are numerous fungal diseases that can cause dark spots on tree leaves and affect their overall health. Anthracnose, for example, is very common in maple, oak, dogwood, and sycamore trees, while Guignardia leaf blotch is common in buckeye trees and chestnuts. Trees can be particularly vulnerable to fungal infections when the weather is cool and wet.
2. Bacterial Infections
Many fruit trees, including pears, quince, apple, and crabapple trees, are susceptible to bacterial infections like fire blight that can cause unsightly blotches on the leaves of affected trees. These spots usually start out pale and indistinct but turn dark as the infection grows more intense.
3. Parasitic Infections
There are parasites known as nematodes that affect certain kinds of trees. One disorder they cause is "Beech leaf disease," which can cause large, irregular brown spots on tree leaves while eating away at the tree's roots.
4. Insect Infestations
There are all kinds of insects that like to feast on tree leaves. Aphids and mites are pests that can be especially difficult to keep out of your yard or garden, and they can leave brown patches behind both from their feeding activity and their secretions.
5. Environmental Stressors
Finally, climate change and unusual environmental stressors can also cause trees a lot of distress, which can manifest in brown or black spots on the leaves. Extreme heat, drought, and poor air quality can all contribute to the problem.
What Can Be Done About Leaf Spot Problems?
If you have leaf spots, the first step toward a solution is identifying the exact species of trees that are affected. Consulting a tree care services company for accurate identification is wise. Once the species of tree is identified, your tree care specialist should be able to narrow down the possible causes of the leaf spots and make a diagnosis.
Treatment, of course, depends on the cause of the problem. Professional application of anti-fungal or anti-bacterial medication may save your trees from further harm, while some trees may need to have infected leaves and branches removed. In some cases, a whole tree may need to be removed and replaced to keep any disease or infection from spreading.
For additional tree care tips, reach out to a local service.