The crown of a tree is the area that holds all the foliage of the tree; essentially all the branches and leaves that extend from the trunk or main stems of the tree.
The crown is the whole area from where the trunk and main stems of the tree end and where the limbs extend to the canopy. The crown influences how a tree functions, its condition, and its appearance.
What are the functions of the crown?
The crown, understandably, is an incredibly important part of the tree, major functions of the crown of a tree include:
- Release of energy via photosynthesis and respiration
- Carbon dioxide absorption
- Movement of water to the atmosphere by transportation
When you speak to tree surgeons about pruning your trees, then the terminology you might hear include tree crown reduction, crown raising, crown thinning, and pollarding.
We’ll talk about each one in turn, but in this article we want to focus on a technique we are called upon to carry out more than any other, tree crown reduction.
What is tree crown reduction?
A tree crown reduction is a pruning technique that maintains crown health and structure.
Arborists focus on taming the upper portion of the tree’s canopy. Usually, branches are cut shorter to decrease a tree’s height. However, a reduction can also involve removing branches that are overly long, heavy, or damaged.
Not all species of trees are suited to this style of treatment. Others may be protected and require permission from your local authority.
This procedure involves careful planning and attention to detail. All cuts need to be precise as over-pruning can seriously affect the wellbeing of your tree.
Benefits of a tree crown reduction to the tree
Knowing how important the functions of the crown of a tree are to the environment, we need to have a good reason for reducing its crown.
For the tree, the main goal of crown reduction is to help it thrive. As they mature, trees can encounter several issues that impact their health. Branches can develop cracks, becoming susceptible to disease or decay.
Environmentally, benefits to the tree of a crown reduction also include:
- Reduction of shade or light loss that may affect the growth of nearby plants
- Decrease in the number of branches that are competing for sunlight
- Increase in light and fewer competing branches can promote healthier fruit trees and increased fruit production
- Encouragement of new growth in a declining tree
- Reshaping or rebalance a tree after damage caused from storms or previously poor pruning
- Help in preventing potential damage from future storms or strong winds
What are the other benefits of crown reductions?
Crown reductions aren’t just beneficial for the tree receiving treatment. Overgrown and uncared for trees have the potential to cause an enormous amount of damage.
Mature trees are an essential part of a flourishing environment. They provide homes for wildlife and contribute to the quality of the air we breathe.
- Trees that are left to grow can jeopardise the safety of people and property so crown reductions can help reduce the weight of limbs that could be potentially dangerous
- The growth of trees might see branches becoming tangled in overhead power lines or telephone cables, causing huge disruptions
- Bad weather or undiscovered issues can lead to low-hanging or falling branches potentially damaging homes, gardens, and cars
These scenarios can cause human injury or even death and these problems are entirely preventable thanks to procedures like crown reduction.
How much of the tree can be removed?
Each reduction acts as a slight wound that a tree must heal, so the size, amount, and location of cuts are crucial factors that impact tree survival. Cutting back around 30% of growth seems to be the general rule. However, every tree is different.
Ash, Lime, Poplar, Sycamore and Willow are species that can tolerate heavier crown reductions, whereas Beech, Cherry and Oak will struggle and may die back if pruned too vigorously.
It is best to seek the opinion of a professional tree surgeon before altering your tree.
Can I not just reduce the height of a tree?
When you need to reduce the height of a tree, tree crown reduction is the method, not what is called ‘topping’. Topping is an outdated practice of pruning that cuts branches with no regard for tree care.
Topped trees are likely to suffer from extreme stress and potential failure as they continue to mature. The large wounds become an access point for decay and the tree fights to make up for the lost food source.
And as a topped tree is not considered to be an acceptable pruning practice, any damage caused by branch failure from a topped tree may be viewed as negligence.
A word of caution
And a word of caution: many trees are legally protected so check for Tree Preservation Orders or Conservation Area restrictions. Felling, or even just pruning a protected tree, without the appropriate permissions may result in criminal charges. And do keep a check on the guide to trees and the law.
Check with your local council or ask the advice of your trusted professional tree care company or recognised tree association, as often such big tree care work is best left to the professionals.
And there you have it! You now know the ins and outs of tree crown reduction: what it is and why it is needed. If you notice one of your trees looking a little overgrown or in need of some care, contact a professional immediately.
