I have a 5 year old red oak tree in the front yard. It's about 20 feet tall. A couple of years ago I noticed sap oozing out in an area on the trunk about 2 feet from the ground on the side facing due west. I used a sealer, and that worked until recently. Today the bark in that area is flaking off leaving a scar in the wood beneath about a foot long. Sap does not appear to be coming out.
What is this and what can I do? Should I just leave nature take it's course?
