By Gary Allen Burns
The ABCs Field Guide to Young & Small Tree Pruning uses the acronym ABC to guide us in tree pruning to prevent structural problems done the road. The three categories of pruning are (A) apical dominance pruning, (B) bad branches and (C) competing branches.
In apical dominance pruning of a large tree, you encourage the central stem’s dominance by using reduction cuts to suppress codominant stems.
Bad branches include broken and rubbing branches, as well as diseased and dead ones. Suppress over-extended branches with reduction cuts, as these branches are prone to failure and apply torsional stresses on the tree. And lastly, competing branches can be pruned with reduction cuts to codominant stems. Focus on the central stem and work on the competing scaffolds and branches.
Good pruning practices include limiting heading cuts to twig-sized branches and pruning wounds. Exposed heartwood is more likely to become infected by decay fungi. It is best to remove larger branches over a period of time.