Pruning Young Trees; The TREEfecta Checklist
Structural training is a type of pruning for young trees to help develop proper branching patterns and structure. Negative impacts of poor structure are not prevalent when trees are young. However, as trees grow, and weakly-attached limbs become larger, structural issues can become a point of failure. Understanding the biology of trees can help the process of creating well-structured trees in our urban landscapes.
STEP #1 = Identify the Central Leader
Decide if the tree type is important to have a central leader. This is important because the central leader often dictates the overall growth and form of a tree. When issues with central leaders are not corrected, it can develop into a major structural flaw down the road.
Note from The BIG Oak = Some trees, specifically ornamentals such as Pagoda dogwood, crabapple or hawthorn, will not require a central leader. These trees generally have a more rounded crown and often do not get large enough for substantial damage.
Which of these two limbs will be the only remaining central leader? The other limb must be removed or reduced.
STEP #2 = Remove (or reduce) Competing Central Leaders
Select the central leader of the tree and remove (or reduce) any competing leaders. This is important because this central leader often dictates the overall growth and form of a tree. For trees with smaller competing central leaders, remove the weakest one. For trees with co-dominant limbs that are too large to be removed with one cut, subordinate (reduce) competing limbs to minimize their dominance.
This competing central leader was small enough to prune out (indicated by red line).
This competing leader was too large for one cut, so several smaller cuts were done to reduce the left side (red dots). The remaining leader can now grow and become more dominant.
STEP 3 = Prune Non-essential Limbs
First prune out dead, dying and diseased limbs. Next, prune out redundant, co-dominant, rubbing or crossing limbs. The linden tree pictured below has 3 limbs occupying the same general space. Essentially, two of the three limbs should be removed, with only the strongest limb remaining.
STEP 4 = Select the LOWEST permanent scaffold limbs.
Once these limbs are selected, a decision can be made regarding all temporary limbs. For the swamp white oak pictured below, some of the limbs below the black line (lowest permanent limbs), can be kept short-term depending on the tree size and location. Eventually all limbs below the black line will need to be removed for sidewalk and street clearance.
STEP 5 = Select All Other Scaffold Limbs
Once all other permanent limbs are selected, any additional limbs can be addressed. We have already pruned out dead limbs, dying limbs, crossing limbs, redundant limbs and possibly some lower temporary limbs. With all of these unnecessary limbs and now identifying the permanent limbs, there should only be a few limbs remaining to address.
