Liriope’s Muse: Tree Care Tips from a Master Arborist

Liriope's Muse - CODIT: A Trees Healing

CODIT begins immediately after a tree is wounded. On a cellular level, the trees cells begin to form “Walls” around the wound, preventing or slowing the spread od disease and decay to the rest of the tree. There are 4 walls in the process of CODIT:

Wall 1: the first, and the weakest wall, is formed in the vertical vascular system above and below the wound inhibiting the vertical movement of decay organisms. This wall is made up of gums, resins, and tyloses (all products of the vascular system).

Wall 2: the second, and second weakest, is the tangential wall. This barrier is formed by the last cells in each growth ring and inhibits the spread of decay inward.

Wall 3: the Third, and strongest wall at the time of the wound, is composed of ray cells. These cells inhibit the movement of decay around the stem (or in a radial direction), creating a maze-like barrier.

Wall 4: the fourth wall, also known as the barrier wall, is the strongest with its ability to completely isolate and compartmentalize the decayed tissues that have formed. This protective wall is formed by the cambium layer directly following the trees injury. It works by restricting the movement of decay into other tissues formed after the wound. The cells that make up the fourth wall contain thick walls and chemicals that are toxic to decay organisms.

The effectiveness of CODIT can vary based on the tree species and the nature of the wound, but it is a critical mechanism that helps trees manage and limit the damage from injuries.

CODIT and Pruning

A tree's response to pruning depends on the size, location, and nature of the cut. Improper cuts or cuts too close to the trunk or leaving large stubs increase the risk of decay and structural weakening. While trees don't heal wounds, they can close smaller ones and form protective barriers around damaged areas. Poor pruning makes trees more vulnerable to decay and instability, so proper pruning techniques are crucial for tree health.

Resources:

https://mntca.umn.edu/sites/mntca.umn.edu/files/2021-01/CODIT%20Booklet.pdf

https://www.bartlett.com/resources/compartmentalization-of-decay-in-trees.pdf