Oak wilt risk after large pin oak failed/fell May 15

Asked May 24, 2017, 5:33 PM EDT

What is the risk that a pin/red oak root system might become infected in the aftermath of apparent tree structural failure where the trunk separates from just below to a few feet above the roots? Should an attempt still be made to coat the portion still attached to the root portion a week or more after the failure event? Should the remaining attached portion be cut down to below grade and then coated and/or covered with soil, or treated chemically to kill the roots? A very large red oak is at a distance of 48 feet. White oaks are at distances 25, 36 and 43 feet. Small pin oaks aged 20 years or less are at a distance of 36 feet, all three of which were damaged when the large pin oak fell. These three could be cut down at grade or below grade now or after July. Please suggest wilt prevention options. Perhaps a wait and see stance is more appropriate. Or perhaps further steps might depend on whether or not I can find out if oak wilt is currently within 1/4 mile of this fallen tree. Images attached.

Washington County Minnesota

1 Response

You can recut and seal it immediately but that is no guarantee that the fungus or insects have not already entered the tree. The next step would be to trench and/or use chemicals. These you should contact a certified arborist to do. The attached links will tell you everything about oak wilt and how to manage it. Studies in St. Paul found that the area of spread was highest up to 30 feet but there was some beyond. I didn't quite understand if the tree that fell was infected. Did it die very suddenly? It might have already been infected in which case you may already have oak wilt in the other trees. http://www.extension.umn.edu/environment/trees-woodlands/oak-wilt-in-minnesota/ http://www.dnr.state.mn.us/treecare/forest_health/oakwilt/index.html Oak wilt happens very quickly in trees; so if the tree died suddenly(within a couple months) it is likely to have been infected. A certified arborist can help with these decisions.