The dormant season is upon us and there is no better time to prune your trees. When trees are pruned during this time, the resulting wounds are less likely to weep, there is less risk of infection by certain types of diseases, and the wounds are ready to callus vigorously in the spring. If not conducted properly, pruning can be irreversibly damaging. The two most important factors to consider are the type of pruning that should be performed and the quality of the pruning cuts. Here are some suggestions on how your trees can get the most out of a good “haircut”.

The International Society of Arboriculture recognizes 4 general types of pruning: Cleaning, Thinning, Raising, and Reduction. Cleaning includes the removal of dead, dying, diseased, crowded, and weakly-attached limbs. Through the select removal of branches, a Thinning Prune improves light penetration and wind flow through the canopy. Thinning also helps to reduce unnecessary weight and improves the shape of the canopy. By removing low limbs, Raising improves clearance and visibility. As the name implies, Crown Reduction reduces the overall size of the canopy. However, in contrast to topping, Crown Reduction maintains the structural integrity of the tree. Your trees may need one or a combination of these types of pruning. Just remember, you should never remove a limb without a reason.

The notion of proper pruning cuts has been best described by the late Dr. Alex Shigo. Dr. Shigo’s research on compartmentalization of decay in trees, or CODIT, has led to better understanding of our trees’ natural defenses and how we can work with nature to maintain their health. By avoiding stub cuts and flush cuts, the branch collar is allowed to form callus tissue and begin the process of compartmentalization. More important than any paint, tar, or wound dressing; natural compartmentalization is the tree’s only true defense against disease and decay.

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