Tree wounds are normal. The causes are broken limbs, animal damage, insect attacks, fire, abrasions, scrapes, etc. Wounds typically damage the water and food conducting tissues as well as break the bark. In addition, wounds expose the tree’s interiors to bacteria and fungi. This is why tree wound repair work should be done immediately after wounding, so the tree remains healthy.
Tree Response to Wounding
Trees respond to wounding in two ways: the development of barrier zones and compartmentalization.
Barrier Zones
Not only do trees attempt to close the destroyed tissue from the outside, they also make the current wood surrounding the wound unfitting for spread of decay organisms. Though these processes are not well understood, the tree tries to avoid more injury by setting physical and chemical boundaries near the infected cells and confining the damage.
If the tree is effective and quick with its boundary-setting mechanisms, the infection stays localized and doesn’t spread. Though, if the mechanisms aren’t efficient, the infection will spread. Most actively growing and vigorous trees are successful in coping with decay-spreading mechanisms.
Compartmentalization
When a tree is wounded, the damaged tissue is not fixed and does not heal. Trees don’t heal. Trees seal. If you examine an old wound, you will see that it does not heal from the inside out. Ultimately the tree covers the opening by producing callus tissue around the wound’s edges.
After wounding, new wood grows around the wound, creating a protective boundary stopping the decay or infection from going into the new tissue. Thus, the tree reacts to the damage by “compartmentalizing” or isolating the injured, older tissue with the slow growth of healthy and new tissue.
Physical Repair
Tree wounds usually look raggedy where the bark is cut during the injury. This is typical during branch breakage and when the trunk of the tree has been scratched. To repair this sort of damage, slice off any raggedy bark edges with a sharp knife.
Be careful not to cut off the healthy bark and bare more live tissue than necessary. If possible, the wound needs to be oval shaped with the long axis going vertically along the limb or trunk. All bark around the wound must be tight. Call Tampa Tree Service if you are unsure about doing the work.
