This afternoon’s arborist-centric learning seminar at New England GROWS, the three-day green industry conference & expo held at the Boston Convention & Exhibition Center, dealt with the how’s and the why’s involving structural pruning of young trees. Specifically, the seminar highlighted why young trees should be pruned at planting as opposed to after-the-fact.
Ed Gilman, Ph.D., professor of urban trees & landscape plants at the University of Florida, was the seminar’s speaker and moderator. Highlighted points of Gilman’s seminar included:
- How to maintain a proper aspect ratio in planted trees.
- The importance of a dominant leader to the overall structure, health and aesthetic success of a tree.
- The importance of pruning trees at the planting stage. Though tradition may say otherwise, pruning trees at a young age can make all the difference as the years progress and the tree takes on an ideal form. Consider, is the tree in question likely to receive structural pruning in the net 15 years?
- When trees come from growers and nurseries, the structure of these trees is likely not arborist-friendly or sustainable. In the United States, growers do not often set up a tree’s structure with longevity in mind (In other countries, like Amsterdam, the opposite is true). Then it becomes the job of the arborist to improve this structure with proper pruning techniques.
- Proper reduction cuts are better management practices than hasty removal cuts, or “lion tails.”
- Better tree structure always equals longer life.
- Structural pruning reduces the growth rate in pesky, less-desirable low branches, especially in cityscapes.
- Arborists should reduce the occurrence of upright stems that compete with the tree’s leader.
- If lower branches will be removed eventually, keep them short initially.
- Other structural pruning tips include: Identify the lowest branch in the permanent crown, prevent branches below the permanent crown from growing too large, space main branches along the dominant trunk, keep all branches less than 1/2 the trunk diameter by shortening or thinning them and suppress growth on branches with included bark.
Gilman’s points, tips, further instructions and information can be found online here.