Do trees heal?

Submitted By ~ Corry Mordeaux

Guess what? They do not!

Wait a minute…I prune my tree and the wound heals up. Nope! Let me introduce you to the funny abbreviation “CODIT”. This stands for Compartmentalization Of Decay In Trees. OK, this is pretty fuzzy. Let’s dig a bit deeper.

We need to look at trees as being a tree within a tree. Each annual ring that you see in a cross section is actually a tree. (Illus. 1 below)

trees 1

Illus. 1

trees 2

Illus. 2






If we look at a cross section of a tree, we see the annual rings (tree within a tree) but we also see ray cells from the center to the outside. (Illus. 2 above)
Now hold those two pictures in your mind for a moment. As you well know, animals heal or restore a wound or infection to a healthy condition. Trees wall off or compart-mentalize injured tissues. Trees have no healing abilities. They wall off or isolate the injury. With the previous pictures in mind, CODIT is based on “walls” …top, bottom, and sides. These walls are in the growth rings and are penetrated by “tubes” (vessels or tracheids).

Some organisms and insects are able to continue to work through the walls. The cambium forms the most important barrier wall separating infection from new wood. This new wood is seen growing around a wound.

A good example of CODIT is provided by the reference for this article. “trees 3Another way to look at this situation is to show how it is similar to a battleship. A battleship is a very slow moving vehicle. It is highly compartmented. When it is hit the survival of the ship depends on the ability of the crew to close off the areas hit by a shell or torpedo. When the crew is very active and the ship has preset construction that permits effective walling off, the ‘injury’ can be limited to a small space. But, if the crew is sluggish, and the preset construction of the ship is weak, then the injury could cause severe problems – the ship could sink.”

The basis and diagrams for this article come from the National Arborist Association Home Study Course and is based on research conducted and published by Dr. Alex L. Shigo.