I know the were some studies done and it made no difference if it was painted or not ,some folks paint because it looks better . The tree will heal, a better word is seal itself, callus tissue will form around the wound ,protecting the tissue on the inside from infection and decay . Here's a link to a more detailed explanation. http://essmextension.tamu.edu/treec...ree-damage-and-hazard-assessment/tree-wounds/
We used to always use tree kote or paint the ends but that was years ago. We no longer do it and it has worked out fine. For example, we have an oak in the circle in our driveway and I took a big part of it down about 30 years ago. All is fine and well.
