Oak pruning and Wisc. DNR date

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antigrassguy

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http://dnr.wi.gov/org/land/Forestry/Fh/oakWilt/
This is what the Wisconsin department of natural resources puts out as a info pamphlet concerning oak wilt. Good stuff BUT I have an issue with them placing a date, April 15, as the last day to prune oaks till fall. The reason I dont like this is that our weather has above the average for almost 2 weeks and todays temps are upper 70's and more to follow this week. This weekend I have received 6 calls from folks that want to know if I could come by to trim their oaks. I tell them that we have stopped trimming on oaks but I would look at them and set it up for next season. At this point I am informed that the WI DNR says its OK to trim till 4/15. I than try to talk about how many bugs they have seen and if they are so inclined I would bring up fungal mat spores and how bugs and fungus aren't real good about checking in with the DNR to see if they can go out and play. So todays winner says "I need this done so I can put up a gazebo". Its a red oak and oaks not 2 city blocks away are dropping like flies last fall. I offer to inject the tree, first, then I would be willing to raise it up for his project. "Sounds like your trying to sell me something I dont need cause the DNR says its OK". Not exactly verbatim but close enough.
SO question for folks at what point do you quit pruning on oaks and elms? By the calender or by your experience and the weather?

FWIW the out of state vacation home owner said he was going to call someone else to hack on his tree. Im glad hes gone.
 
Keep track of the accumulated growing degree days. At what point do picnic beetles start flying? Base your decision on that. And you are right - April 15 doesn't mean the same thing in Walworth as it does in Sayner. However, the basis of that date came from a compromise with the line clearance folk.
 
April 15th is a conservative safe date

According to the people at the University of Minnesota, they have never seen a spore mat before May 10th. Doesn't mean they don't exist before that, but thats what they say. I believe they chose the April 15th date as a safe time to allow the pruning cuts to dry out and took into account early springs.

This is for Minneapolis though.


Elms are earlier April 1st. Emerging beetles are carrying the disease and need no fresh source. Wounds attract them.
 
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