Pruning Tips 1: Establishing a Leader
Published on April 8th, 2020 by Aaron McFarland
TreeLab Manager, Aaron McFarland, here and it is an early spring this year for sure! For those of you who have smaller trees or shrubs in your yard, now is a great time to be pruning (most things, that is)! In this blog post, I’ll be showing you a pruning technique to use on trees that are developing multiple “leaders”. At the end, I’ll include a few helpful links provided through Virginia’s Extension Office services that’ll help you determine when the right time is to prune the plants in your yard, as well as the proper way to do it.
Here at TreeLab pruning is an important part of our plant production processes. A lot of our trees and shrubs are planted at schools, parks, or as street trees, and their post planting care isn’t always a guarantee. Therefore, I do my best to prune for proper structure over the aesthetic value. I recognize that sometimes our plants don’t get much pruning attention after they’re planted, so we do our best to set them up for success in the future.
Today’s example is a red maple (Acer rubrum) that is growing at TreeLab’s Amelia Street School location. We received these trees as a donation and it is quite clear from the branching structure of the trees that they have been pruned only for aesthetic value, not for future health.
This close-up view of the co-dominant stems is a dead giveaway that this tree will have major problems in the future. You can see at the union of the branches to the main trunk that their diameter is too large compared to the main trunk. These branch unions are prone to failure down the road, resulting in potential large branch breakage. This is a problem that was not addressed when the tree was at a younger age. Although I will create large wounds, I will likely cut these two side branches off and hope that the tree is able to recover. If not, I would have deemed this tree unworthy for use anyway and likely would have scrapped it.
For the purpose of this example, I will not be cutting away the two side branches, but rather pointing out the branch trying to establish itself as the new leader.
Moving up the tree, we look for branches to prune so that we establish one main leader. As you can see the branch on the right of center is attempting to become the new leader. I prefer to keep the original straight, center branch as the main leader and trunk of the tree.
In this picture I am making a pruning cut on the straight branch that is attempting to become the new leader. Assuming this branch had a proper attachment to the main trunk, this pruning cut would help to ensure that we keep one main leader. Furthermore, by removing the leader from this branch, we are creating a chemical reaction in the tree that will cause it to force more growth to the lateral (side) branches/buds.
This is a step we take every year with most of the trees we grow (not all trees naturally grow with a single leader) and will prune out any new co-dominant leaders we see throughout the growing season, even if it is outside of the ideal window to prune. Making these pruning cuts early, when the branches are small, allows the tree ample time to seal off the wound and within a few years you will never notice it happened.
Keep an eye out for more content soon where we will discuss more in-depth pruning pointers.