Oak Wilt?

Asked August 28, 2015, 4:31 PM EDT

Can you tell what these oak leaves are suffering from? They have been turning yellow and brown and falling since late June. Recently even faster. Our oaks are the last to lose their leaves in the fall. This one is now the first. Leaves are almost all down.

Otter Tail County Minnesota

1 Response

Oak wilt is a serious disease that is spreading in our area. It's not the only disease that is threatening our oaks, however.

Your tree appears to be in the white oak family - possibly a bur oak. While oak wilt can affect both red and white varieties, red oaks are more susceptible.

Here is some information about Oak Wilt:
http://www.extension.umn.edu/environment/trees-woodlands/oak-wilt-in-minnesota/

Here is some information about Bur Oak Blight:
http://www.myminnesotawoods.umn.edu/wp-content/uploads/2010/09/BOB-factsheet-2011may-USFS-pest-alert...

Finally, this has been a very wet year and many trees are showing signs of Anthracnose - a fungal disease that causes the leaves in the lower parts of the tree to turn yellow and brown, and drop early. This is not a serious disease, but good sanitation (raking and removing leaves all year) helps to lessen the impact. Here's some information about Anthracnose:
http://www.extension.umn.edu/environment/trees-woodlands/oak-wilt-or-anthracnose/

In any case, you may want to contact a certified arborist who can come out to your property, assess and diagnose the tree and make recommendations about either treatments, or removal:
http://www.myminnesotawoods.umn.edu/2009/01/finding-tree-care-help-certified-arborists-and-mn-tree-c...

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