Maple Leaf Tar Spot

There is a fungus on my maple trees and it is called Maple Leaf Tar Spot.  It is easy to identify due to the black spots on the leaves.  It is caused by a fungal pathogen which affects maple trees, especially the Norway Maple, Sugar Maple and Silver Maple.

Thinking that the trees would be harmed by this fungus, I had the lawn and tree service spray the maple trees this past spring and periodically thereafter through the fall.  This service was expensive and to no avail. The spots returned. They first appeared as small yellow spots in June, then progressed to the familiar black spots, some of which were 1/8 inch in diameter. By mid-August, many of the leaves had dropped to the ground.

Disappointed by the reoccurrence of the fungus, I decided to consult a certified arborist who confirmed that the trees had the Maple Leaf Tar Spot fungus. After learning that the fungus is not fatal like the Dutch Elm Disease. I asked about treatment and prevention.

Spraying the trees was not recommended as a treatment or prevention.  The advice seemed simple and reasonable. Fall leaf clean-up was crucial. The most important reason is that several prolific tree problems originate in dead leaves. Dead leaves harbor several types of fungus that can winter-over underneath the snow.  This moist environment is perfect for the fungus to multiply in the spring, spreading to the tree’s leaves.  When the spring is rainy and cold like it was last spring, the chance of having the fungus reappear is inevitable. However, if we are fortunate to have a warm, dry spring, the fungus may not return.

Lesson learned from this . . . it is best to consult and follow the advice of a certified arborist. The fee of $45.00 for the arborist to check all seven trees on my property was far less than what the other service charged for the spraying.

Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s

%d bloggers like this: