Tar Spot on Maple

tar spot fungus on maple tree leaves

Do you see these tell-tale markings on maple leaves in your area? This is a common fungal disease called tar spot.

Tar spot is caused by warm/wet environmental conditions in the spring and is almost never a serious threat to the health of your trees, just an eyesore. It can cause some early leaf drop but well-established maples can usually withstand this stress factor just fine.

If you see symptoms of tar spot on maples, we don’t recommend any spray application but you can take steps help to stop re-infection of new leaves. While you can’t control the environmental factors that allow this fungus to thrive you can slow the spread by raking up and removing or destroying infected leaves when they fall. Normally we recommend mowing leaves where they fall but always make an exception in fungal conditions!