Does your maple have black spots? Then the tree probably suffers from tar spot disease. Here you can find out how to react to this fungal infestation and avoid future illness.
What causes black spots on maple trees and how to treat them?
Black spots on maple trees are caused by tar spot disease (maple scab), a fungal infection caused by Rhytisma acerinum. To treat the disease, consistently remove infected leaves and avoid shady or damp locations for new plantings.
Why does the maple tree have black spots?
Black spots on the leaves of the maple are typical symptoms of the disease also known asmaple wrinkled scabTar spot disease This disease is caused by a fungal infection. In this case, a fungus called Rhytisma acerinum is responsible. The fungus continues to spread. If you don't intervene, the leaves will not only change color. The disease also results in early shedding of leaves.
When do black spots appear on maple trees?
Tar spot disease typically occurs inwet springs. The rain brings moisture with it and thus promotes the spread of the pathogen. The fungus can also survive the winter cold on infected material. If you don't treat a sick maple tree with black spots, the damage can reappear on the tree next spring.
How do I treat a maple tree with black spots?
Removetheleaves with black spots from the maple location. If possible, collect all of the affected leaves from the tree. You should also not leave fallen leaves lying under the sick maple tree. Otherwise, the pathogen will survive the next winter in place. Collect the leaves and dispose of them in a closed trash or burn them. There is currently no effective fungicide to combat maple scab spores.
Where does maple scab often occur?
AvoidshadyormoistLocations are best when planting the maple. A humid climate can develop in these locations, which the fungus prefers. If you instead plant your tree in a dry location with enough sunlight, you can in many cases avoid the fungal infection from the outset and you don't have to worry about black spots on the maple.
Which maple variety is most often affected by the disease?
The Norway maple is particularly susceptible to tar spot disease. However, infestation can also occur on other types of maple. However, to avoid the black spots on the maple, choosing a different type of maple and a suitable location offer good options.
Tip
Collecting the maple leaves with black spots is enough
There is also positive news in connection with tar spot disease: This is a local fungal infection that is limited to the leaves of the plant. Therefore, it is enough if you remove and collect all the leaves with the black spots. So you don't have to worry about pruning the maple.
