The repair of the tree usually consists of removal of the stubs of limbs back to the tree trunk, with careful attention to the preservation of the branch bark collar. The collar, the ridge of tissue at the junction of the limb and trunk, contains special tissue composed of meristematic cells. These are akin to stem cells in humans, having the potential to develop into whatever type of tissue the tree needs. In the cambium, for example, the meristematic cells produce the xylem and phloem tissues, in the limb tips it produces terminal buds and linear growth of the stem and in the roots it is responsible for root growth. These same cells produce a covering over the wound resulting from limb amputation. The ability of the tree to cover the wound prevents infections and preserves longevity.

The pruning of the limbs broken towards their tips should be back to a lateral branch of that limb which is at least 1/3 of its diameter. That cut should be on a slant, paralleling the collar of the smaller limb to which it is cut back. Ninety degree cuts are rarely indicated. When encountering a long limb that will need cutting back to the tree trunk, use the 3-step cutting technique to prevent tearing of the trunk bark. This consists of a cut on the limb one foot out from the trunk upward, about 1/3 of the thickness of the limb. Next, 2 inches out further from the trunk, cut downward until the limb is severed and drops. This leaves a stub, the cut of which is described above. Additional tree repair could include a need for bolting and cabling of the trunk. This is very specialized and must be done by an arborist.

Repair work you should not allow includes cutting off limbs of trees flush to the trunk. As indicated above, this prevents proper healing of the wound and leads to infection and cavity formation of the tree. Another all too common pruning activity is “hat racking”, also called heading or tipping. This consists of cutting all limbs back to stubs. It has been done in the past to shorten trees under structures and is done now, after ice storms, by unknowledgeable or unscrupulous tree pruners. When done, this removes a hormone called auxin which is produced continuously in the terminal bud area of tips of all limbs. Auxin suppresses the development and growth of all types of dormant buds on that particular limb. When the hormone and the suppression is removed, there is unrestrained growth of all buds. Many of these buds, which were not meant to produce stems, develop slender rapidly growing stems called water sprouts or suckers. These stems are anchored to the limb very superficially and tear off readily with subsequent ice or wind events. The tears are then sites for entrance of infections and insects resulting in a greatly shortened life span of the tree. Moreover, the tree never looks as that particular species was meant to appear. They are ugly and reminds one of a hairbrush.

To remove a tree or not to remove: that is the question. Whether ‘tis nobler in the mind to suffer the tree damage of outrageous fortune, or to take arms against a sea of stubs and by sawing to remove them. Well, Shakespeare’s Hamlet notwithstanding, the dilemma is whether to remove a tree that is marginal,now or wait and see how it performs. Waiting may involve up to 5 years of observation before the tree becomes diseased and declares itself a failure. On the other hand if you decide to remove the tree now and opt for the largest tree you can afford, you will have 5 years of tree growth on your new tree in the same time frame. A compromise may be to give it one year and unless encouraging new growth occurs, remove it then.

If you do need to replace the tree there are several considerations other than choosing a tree that grows well in Oklahoma. You should always consider the ultimate size of the tree. Many trees are planted too close to structures, each other and too close to utility lines. The recent storm emphasized that all too clearly. When selecting trees according to size especially as it relates to power lines, consider consulting the “Tree Tips” booklet provided free by PSO. This is an excellent reference for tree size, flowers, growth requirents, etc.

Features that make trees susceptible to ice damage are broad crowns (more surface area), unbalance crowns, multiple small branches, narrow angles of limbs to trunks, lack of maintenance pruning, shallow root systems and retained leaves (e.g. oaks). Also putting the tree at risk is a growth feature called retained bark. This is bark grown down into the junction between a limb and the trunk, like an ingrown toenail. This is a common characteristic of bradford pears and, along with their narrow limb/trunk angles are causes for their susceptibility to ice and wind damage.

Features favoring survival of trees in ice storms are basically the opposite. A resistant tree is more likely to have a pyramidal shape, a tapered and elastic trunk, fewer and stronger limbs with attachment to the trunk approaching 90 degrees. This tree would have regular maintenance pruning of dead or diseased material.

A list of trees and their susceptibility and resistance to ice damage is below. This has been extracted from the Hauer article and modified for our region. This is by no means inclusive. For trees not listed, look for close relatives on the list and apply the characteristics of ice damage relationships mentioned above to make an intelligent guess.