How to respond to oak tree damage?

[BillyB]

I lost a large limb from an important red oak in a storm the night of 7/11/17. The wound covers an area of about 10 sq ft and is 20-25 feet in the air. Trees had suffered oak wilt less than a hundred yards away. Please let me know whether you think something should be done to protect this tree and, if so, what? Appreciate the advice, thanks! Open image in new tab (windows-right click):

 

[ATH]

Photo doesn't show up. I would strongly consider having it treated with Alamo. You are just past the primary infection period, but probably still worth it in my opinion. Find a company with good arborists and experience dealing with oak wilt...

 

[BillyB]

Thanks ATH! Do Weighing pros and cons of treatment including indefinite outcome, additional wounding, toxicity, and cost, treatment seems worth considering. you think it ok to wait for signs of infection before treating with Alamo? What is the treatment window and optimal timing?

Regarding Coating: I've read coating becomes ineffective for oak wilt after 3-4 days. After this time, is there any further reason to coat? If so, with what and when?

 

[ATH]

Indefinite outcome and cost would be the 2 biggest factors I'd weigh. While there is minor wounding with injection, I compare that to thinking of it like mi or surgery...yes, a Doctor would rather you not be cut open, but the alternative of not doing that is worse than the cut (at least it should be!). Cost is always a factor...but what would the cost of removal be? That is where indefinite outcome weighs in.

You are correct about wound treatment. If it has been more than several days, just leave it. However if there is a jagged stub left it may be a good idea to prune that. I'd wait until fall, but if it is done now, treat that new wound.

Finally: while you CAN treat infected trees, success rate will be higher with preventative treatment. How recently were those other trees nearby killed? Have you seen any oak wilt around you this year?

 

[BillyB]

I wish I could show you a photo but I've tried and tried and no luck yet. The best I can do is invite you to open one in your browser: https://1drv.ms/i/s!ArjL0-GXoEVZg6gOLjMRfDs7_r2viw

The picture actually makes it look worse than it is since it is taken straight on. I'd estimate I've lost 35%ish of the circumference of the tree bark in this location. I've been given a rule of thumb that if 25% is damaged, the tree should survive. If 50% or more probably not and should be removed. I guess this rule would put me in a gray area. I would also guess, however, that the cambium/bark/transport system that has broken off was primarily dedicated to the fallen limb. It's loss would consequently impact the remaining tree less than these simple numbers would suggest. To give you an idea of how much bark is left in tact, here is a photo of the tree from the opposite side of the wound: https://1drv.ms/i/s!ArjL0-GXoEVZg6gPMsjaHft6joQ4Ng

I expect you'd agree that the break is flush and that there is no stub but let me know you think my assessment is overly simplistic. I hear you, however, if there was a stub, I should prune it then treat the fresh pruning cut asap.

My neighbor 100 yards away and across the street has been challenged by wilt spreading through his root system. His trees died last year or earlier. We took a couple of the dead ones down this spring and he still has a dead one standing but I have not seen any new oak wilt in the area this year. Is it safe to say that if there is no new wilt, that the threat is likely diminishing?

ATH, I appreciate your thoughtful replies, they are helping me assess my situation, options, and implications thereof. Thanks!