Why prune trees?
Tree pruning is done to satisfy a few different aspects of tree health.
- Removing dead, dying, and diseased limbs.
- Creating a scaffold branching throughout to allow snow and wind to move freely through the tree with less risk of breaking or damaging limbs.
- Shaping and containing plants for aesthetics and most importantly, reducing hazards throughout the tree where possible.
Corrective pruning of small to medium-sized trees
This is where the tree is pruned to foster strong future growth. The removal of crossing, interfering, or unwanted limbs early on is less traumatic to small and medium-sized trees than it would be to a mature established tree. Think of this in terms of adults vs. children breaking a bone. The younger you are the quicker you heal!
This topic is rarely discussed as the typical prune on the east coast and the mid-west concentrates on mostly dead wooding shade trees. This is something that is included here in the Mile High region, but it is necessary for us to do a bit more due to our high plains environment. Simply put, it is not uncommon to have a snowstorm while our trees are in leaf. It is very important to reduce leverage and weight at the tips of our shade trees. This sometimes entails reducing the lateral limbs by a few feet to gain this reduction in tip weight. Sometimes this can be achieved by simply thinning the ends, getting that scaffold look so the snow filters through the tree instead of collecting on the ends. This not only helps to protect from early and late snowstorms but will also reduce the “sail” effect during the occasional micro-burst that we experience. Now, this is where arborists are very important as it is vital to not take too much leaf base out of the tree to the point that it will cause the tree to stress. Remember High School biology class? Leaf base is the engine that drives the plant’s food production. Don’t take too much or the plant will react in a very negative way.
The two most common ways to prune shrubs are natural hand pruning and mechanical shearing with hedge trimmers. Both are acceptable practices and are subject to your interpretation of how you want your shrubs to look when the pruning is completed.
There are some trees that require being pruned while dormant such as Crabapples, Apples, and Hawthorns to avoid diseases like fireblight. All trees can be pruned while dormant, however. How can you tell the difference between what is alive and what is not? As you can tell there are buds on the ends of the limbs that show that it is alive. The dead branches and limbs snap and break quite easily. Without having all the leaves on the trees to climb through, pruning during the winter is the best time of all. Plus there is not as much debris that will fall.