Q: A tulip poplar sits right over our koi pond. It had a fork in the trunk about four feet above the ground. A year ago the smaller trunk of the two showed obvious signs of dying. A tree service removed it. But when I asked them what they were going to seal the scar with, they said it was not necessary. Ever since, the scarred area has produced a black liquid that remains wet to the touch. The remaining trunk seems healthy and full but we’re worried that the bleeding process may be a sign of future problems.
A: The tree people were correct in not putting tar over the wound. Tree wound coatings retard healing.
Because the cut was so large, the tree can’t easily seal it off. Oozing of sap is a normal result. I don’t think you can do anything about it except wash the ooze away occasionally. The oozing should eventually stop. I doubt the tree will ever be able to seal over the cut but there’s not much you can do about that.
Again, the tree heals from inside and will do its best to protect itself without your help.