I have come across an A. palmatum that had a 4" dia. branch removed from a 12" main stem. The work was done during cold weather in early Dec. 2010. The temps. have gone up to the 40's now and the wound is bleeding profusely. I realize there is nothing I can do to stop the bleeding. My question concerns damage to the bark of thin barked Maples caused by bleeding of sap below the pruning cut. What is the mechanism of this damage, and frequent die back of bark?? is it acidity, alkalinity or just being perpetually wet??? Hoping there are some better educated and experienced minds out there than mine, Thanks, James.

I’m not sure exactly what the mode of action might be. Bark necrosis might be caused by infection from the wound intself, and have nothing to do with the sap flow on the outside. The hgigh sugar content of the sap could also encourage colonization by various organisms on the outer bark, which could in turn lead to death of the bark.

The solution is probably to periodically flush the area with water to remove sap residues and reduce any bilogical activity on the bark. The sap flow will eventually stop as the wounded tissues in the area of the cut respond and recover. The loss of sap is not a serious threat to the tree.

Hi Russ, Thanks for the reply. I was planning on washing the residues off the bark but just wondered, if there was a high/low ph. factor whether it was worth trying to neutralize it at the same time.
Now I've made it back in here, I'll try and stop by more often. James.

There’s not much action here anymore, Jim. Your’s is the first post in months. I’ll be changing ISP this year sometime and will probably take the message board down. It served its purpose when I started it, as there were few other good sites for this kind of discourse. The ISA and ASCA started onnline fourums and email discussion lists, and The Knothole dwindled in use.

Bad news Russ. I believe you did a great and wonderful thing when you created the "knothole". You put a lot of time and effort into sharing your knowledge and experience with other people. You brought together a great collection of like minds, also very willing to share their knowledge and experience.I thank-you for the help you have offered me over the years, as well as the help you have offered others. You have certainly established yourself as, not only a very well educated arborist but also, a great guy as well. I hope the demise of the forum will not signify any demise in the relationship built up over the years. Again, Many Thanks Russ. James Causton.