Search

Does Your Maple Tree Have Blacks Spots On Its Leaves?

Share this post:

Tar spot disease on maple trees leaves I enjoy walking my dog every day since it is good exercise for both her and I as well as using that time to look for interesting or unusual plants or turf problems. There is a maple tree disease showing up on its leaves that has become more prevalent in the last few years. The disease is called Tar Spot. It has earned this name because the disease develops spots on the leaves that resemble, well, tar spots.

The disease by itself rarely causes serious damage to the tree, but the spot can become so numerous and heavy that the leaves will drop early.

The disease begins infecting a maple tree in the spring, but the symptoms don’t usually show until mid-June. The disease first manifests itself as small pale yellow spots on the leaf surface. The spots enlarge and they slowly turn into black spots. There are some differences on what the spots may end up looking like at maturity, depending on the species of maple on which it is growing. The disease does not cause any long term damage to the tree, but it can reduce the aesthetic appeal of the tree if the leaves are covered in black spots. The best management practice is to rake and destroy the leaves when they fall during the summer or during normal fall leaf drop. This will reduce the number of spores available to re-infect the tree the following spring. If you wish to mulch the leaves, cover them with a tarp until the following summer. There are disease control materials that can reduce the infection, but it is critical that the entire leaf be covered for effective control. This may be possible on a small tree, but once it gets above about 10 feet, complete leaf coverage will be difficult to achieve.

The better control tactic is to reduce the cause of the infection and rake up and destroy the leaves associated with the maple.

If you are concerned about your maple tree and want it checked for Tar Spot, contact your local Spring-Green professional.