Bark Wounds

Bark is a protective layer that serves many of the same functions as our skin does. When this layer is breached, disease organisms and insects may invade the plant through the break. Directly under the bark is the conductive tissue of the plant--the circulatory system that carries water and minerals to the leaves, and sugar and protein to the roots. If the break in the bark does not heal quickly, this tissue dries out and dies, stopping circulation through that part of the trunk or branch. Bark wounds that encircle more than a quarter of the circumference of a trunk or branch slow the growth of the plant past that point. Small breaks in a healthy tree--those less than ½ inch wide--usually heal within a couple of weeks during the growing season. Larger breaks heal more slowly, as the tree grows a layer of tissue across them. If the break remains open for too long, heart-rot fungi often invade the wound, rotting the wood and beginning the process that leads to hollow trees.

If the edges of a wound are ragged, trim the bark with a sharp knife to make a clean edge, but don't remove any more bark than is necessary. Smooth the underlying wood with a chisel and allow the area to dry. If the wound has begun to heal, a roll of new tissue can be seen at the edge of the wound. Do not cut into this tissue.