I am repairing a split tree trunk by bolting the split portion to the main trunk. At the top of the split, there is an open, uncovered portion showing the trunk center. What inert material can I put in there to protect the trunk center from rain, bugs etc. until the tree grows bark over this damaged area? The tree is basically healthy otherwise.
Certified GKH Gardening Expert
I would gently wrap a piece of plastic over the area, but check it frequently. The biggest danger to a tree in this state is disease. Check to make sure this is not setting in and remove the plastic ASAP if you see it. Do not use tar or other permanent sealers. These can trap disease against the trunk and and you will have no way of removing it if disease sets in.