The amount, depth and location of the damage all come into play when you decide how to treat torn trunk bark. Generally speaking, if the damage to the tree's bark spans less than 25 percent or the circumference of the trunk in the area of damage, a healthy tree may at least partially repair itself by growing a callous around the wound.
Tree bark protects the cambium, phloem and xylem layers ("straw-like" vertical structures) that move nutrients and water up and down between the leaves and roots. Stripped bark destroys these structures so water and nutrients cannot be transported around the entire circumference of a tree. If the bark chunk is 6 inches wide, that's 6 inches of the tree's circumference that can't do its job. If bark is missing in a strip all the way around the tree, called girdling, there is no hope for repair.
A tree's bark is like our skin. If it comes off, it exposes the inner layer of live tissue to disease and insect infestation. It does not grow back. A tree will heal around the edges of the wound to prevent further injury or disease, but it will not grow back over a large area.
Because the cambium "straws" were destroyed in that one area, you will likely see dead or dying branches above the damaged part of the tree. However, if the rest of the cambium is unaffected, the tree should survive.
- Do not paint over a wound with tar or tree paint. Leaving the tree to heal itself allows you to observe the process over the next few years to assure yourself that the wound is healing naturally.
- Do not clean out debris from inside a hole or cavity type of wound, and do not fill the hole with cement or mortar. Doing so will interfere with the tree building up new growth to bridge the gap and to continue transporting nutrients and water from the soil up into the leaves and branches.
If your tree is badly damaged and it is a valuable tree to you, you may wish to consult a certified arborist to assess the damage. Look in the yellow pages or online for local tree services. Ask if they have a certified and insured arborist on staff and speak with that person.