Scraping Wound Wood

[BillyB]

I'm in the process of trimming dead branches from my oaks with either a manual or power pole pruner. Many of the branches are bare of bark down to the trunk where the tree has distinctively protected itself by growing a ring of wound wood around the bare branch. Often, in an effort to trim the dead branch close to the wound wood and because my blade or chain stabilizes against it, I find myself shaving the surface of the wound wood. Typically, it's not a deep shave but enough to show some fresh color on parts of the ring. The branch collar invariably remains.

I know I shouldn't cut the wound wood but my question is, "How bad is this?". The two ends of the scale, as I see them could be:

• It's disastrous for the tree. Fungus will penetrate the trunk from the scraped wound wood and could eventually take a great toll on the health of the tree.
• If the cut is only shallow, it's really nothing to be concerned about. Sufficient wound wood protection likely remains to seal off the branch rot. The surface will harden and the color will darken again with time.

If you have insight into this question, I'd greatly appreciate your opinion. I also invite you to log your response on the above poll.

 

[ATH]

I chose disastrous...but that sounds overdramatic. It is closer to that than nothing to be concerned about.

You are forcing the tree to resources again to respond to wounding. Since the branch died a natural death, that area probably wasn't exposed to several of the sapwood or canker-forming fungi - only those that would enter through the branch. I'd rather leave a tiny stub than cut into the woundwood.

 

[Oldmaple]

I second ATH's response. Check out Alex Shigo's work on compartmentalization.

 

[BillyB]

I chose disastrous...but that sounds overdramatic. It is closer to that than nothing to be concerned about.

You are forcing the tree to resources again to respond to wounding. Since the branch died a natural death, that area probably wasn't exposed to several of the sapwood or canker-forming fungi - only those that would enter through the branch. I'd rather leave a tiny stub than cut into the woundwood.

Not what I was hoping to hear but thanks for clearing up any doubt I may have had. I understand the tree physiology and anatomy behind your response.