Seedless Ash losing leaves

Asked July 29, 2015, 11:30 AM EDT

We have a seedless ash we planted 11 or 12 years ago. It has been very healthy until now. Last year I noticed some black fungus type growth on a the tree in three places. We thought the cold of winter might take care of it. In the last week our ash has started to shed some of its leaves. Do you know what is causing this? What we can do to help the tree thrive again?

Kandiyohi County Minnesota ash trees

1 Response

When you say you noticed black growths on the tree do you mean the leaves or on the limbs or trunk?

This has been a wet year, and we are seeing lots of anthracnose infections in many plants. This is a fungal disease that affects the leaves. It isn't necessarily a problem unless the tree suffers heavy losses for a few consecutive years. Here is some information:
http://www.extension.umn.edu/garden/yard-garden/trees-shrubs/anthracnose/

One of your photos seems to show an entire die-back of the twig that is holding the leaves. If this is common throughout the tree it may be a more serious problem. Here are a number of options that you should look over, and see if the symptoms match:
http://www.extension.umn.edu/garden/diagnose/plant/deciduous/ash/trunkdead.html

I hope this is helpful. Please contact AaE again if you have further questions.