Sealing Wounds – Why is it important?

This was one of the most debated topics a few years back. To seal or not to seal? (to be poetic) Sealing the wound on a tree (a cut, broken branch, scrape, or whatever the case may be) actually slows down the healing process. On all trees except OAKS (all oaks) the wound should be left untreated. The tree will compartmentalize the wound on its own and at a faster rate. ONLY oaks should be sealed here in the Hill Country due to the presence of oak wilt (Ceratocystis fagacearum). Now you do not have to go out and buy the $8 or $9 a can pruning paint, a 99 cent can flat black (black because it blends in well with bark and shadows of the limbs) or whatever color you desire to seal the wound.

There are two main reasons we seal wounds on OAKS. First, once a wound is made the tree excretes sap to keep insects or other pests out. However, the sap attracts the nitidulid beetle which can spread the spores of oak wilt into healthy trees. These beetles can fly 3 to 4 miles from a fungal mat (that is a long way for beetle smaller than your pinky fingernail). The second reason we seal wound on OAKS is to put a layer of protection from the fresh cut tissue to the outside environment. Again, protecting the wound from that rascally little beetle.

If you decide to cut a few branches yourself please seal the wounds on your OAK trees, better yet call the experts and have your trees professionally trimmed….it may save you headaches down the road or even your life (I’ll explain this one in a later post).

Lee Evans
Certified Arbor Care
ISA Certified Arborist TX-1339A