Do trees heal wounds in winter?

[corndogg]

If we do all trimming on oaks in winter and the fungus is active in spring is the wound compartmentalized by spring? The pruning cut is still there in spring and looks the same. Is there activity in the dormant season? Please advise.

 

[ATH]

No growth in the winter, so compartmentalization can't officially start until the growing season starts.

However if it is oak wilt you are worried about the beetle that carries it is attracted to the volitiles that the tree puts out when it is injured during the growing season. Winter wounds are dried out by the time spring rolls around, so oak wilt isn't a concern.

If it is decay fungus you are worried about, any open wound is a fair target...

 

[corndogg]

I was concerned with Oak wilt. So the beetles wont be "attracted" but if one happens to find itself on a wound carrying the fungus then it's bad news huh? So no guarantees with winter pruning. Would it then be better to prune earlier in fall to allow for more drying time. I'm getting calls right now to prune Oaks and I tell them we still have a little time. The closer we get the more risk huh? When do you guys stop and where? For Oaks and Elms?

 

[corndogg]

Decay fungus will get in there regardless but compartmentalizing will handle that in theory right? I tell people not to cut too large a branch relative to the trunk as this will be more dificult to heal and result in more die back into trunk because the tree has a hard time compartmentlizing large wound. Don't want to make easy access for fungal decay that will later weaken trunk. Better to reduce and leave goofy stubby branch cut at lateral with some growth right? Am I on the right track here?

 

[ATH]

Oak wilt:
Nothing I have read talks about the beetle "just finding" the wound without the fresh wound emmiting volatiles. So I can't say it is or is not possible?

As long as you are not pruning during flight time, you are in good shape - and I don't think waiting until September/October will make a difference when it comes to oak wilt. Just avoid mid April through the end of July. If I can't get to the tree before April, I like to wait until September just to be safe (I guess we are almost to April, aren't we...).

Also...just to be clear: this applies to oaks in the red oak group. Not really a concern for the whites.

Here is a USFS article on oak wilt.

 

[ATH]

Decay fungi:
Pruning has been reseached for many decades. Stick with what the research has shown to be best. If you are cutting a lateral limb away from the trunk, the live portion should be at least 1/3 the diameter of what you cutting.

"tipping" a large lateral away from the trunk will still carry decay into the main trunk and you will have a large hollow stub that is going to come off at some point...

Sometimes we just need to make a larger wound than we would like on the main trunk - knowing that this is going to be a door for decay. Plan to check the tree every couple of years to monitor progress of decay.

 

[Urban Forester]

Another factor is the type of Oak it is that your pruning, reds have no resistance. Whites can compartmentalize (the fungus) and survive. Winter pruning on Oaks is the safe bet simply because of no picnic beetles. Macro-infusion of high value red + white Oaks is another option.

 

[corndogg]

By "picnic beetles" you mean anykind of beetle, there are millions I hear, right. No specific beetle that spreads oak wilt? Define macro-infusion. You mean treatments with those little plastic thing you stick in the trunk. Please advise. Iv'e never messed with these. To treat oak-wilt or help ward off fungal decay?

 

[corndogg]

I read the article. All questions answered thoroughly. Very Helpful. Thanks so much. Got any good links on DED.

Thanks Again

 

[ATH]

DED article: From the Forest Service again

The way to find these is seach Google with something like: "USFS dutch elm disease" of "USFS Oak wilt" (USFS = United States Forest Service). The Forest Service has a terrible search engine - somebody at one of the labs actually told me to use Google to search for USFS articles.

 

[Kneejerk Bombas]

Oak wilt:
Nothing I have read talks about the beetle "just finding" the wound without the fresh wound emmiting volatiles. So I can't say it is or is not possible?

There is a time period when fresh wounds are attractive to insects and the vascular system is open to infection from contact with Oak Wilt.
I've seen this time period referred to as being from about a day or two, to a couple weeks.

As long as you are not pruning during flight time, you are in good shape - and I don't think waiting until September/October will make a difference when it comes to oak wilt. Just avoid mid April through the end of July. If I can't get to the tree before April, I like to wait until September just to be safe (I guess we are almost to April, aren't we...).

You want to end your pruning at least two weeks before insect activity.

Also...just to be clear: this applies to oaks in the red oak group. Not really a concern for the whites.

Here is a USFS article on oak wilt.

Why would you exclude this for White Oaks???