Pruning is an essential part of tree maintenance. It helps keep trees healthy and aesthetically pleasing by removing dead, damaged, and diseased branches. But does pruning also reduce root growth? The answer is not so straightforward.
How Trees Grow
To understand how pruning affects roots, it helps to first understand how trees grow. Trees grow upwards and outwards from buds on branches and twigs. These buds contain embryonic leaves and flowers. At the same time, trees also grow downwards as roots extend into the soil, absorbing water and nutrients.
There is a delicate balance between top growth (branches, leaves) and root growth. Trees need leaves for photosynthesis to produce food, and roots to absorb water and minerals. If the balance is disrupted, it stresses the tree.
Impacts of Pruning on Roots
Light pruning of up to 25% of live branches has minimal impact on roots Removing large branches through crown reduction pruning has more significant effects
Crown Reduction Pruning
Crown reduction pruning reduces the height and spread of the tree by cutting back leaders and major branches. This removes a lot of leaf surface area With less foliage for photosynthesis, less food is produced for root growth This type of pruning often results in a corresponding decrease in root mass.
Studies on fruit trees have found that moderate crown reduction pruning (25%) causes a 10-30% loss of roots. More severe pruning (60%) leads to a 45% or greater reduction in root mass.
Crown Thinning
Crown thinning removes selected inner branches to let more light into the canopy. Since it removes less foliage than crown reduction pruning, the impact on roots is minimal. One study found crown thinning on apple trees caused no reduction in root growth.
Timing of Pruning
When pruning is done also influences how much it affects roots The best time to prune most trees is when they are dormant in late winter At this stage, very little energy and nutrients are required for above-ground growth, so the tree tolerates pruning better.
Pruning in late spring just before the main flush of new growth can reduce root mass for that season. The tree has minimal stored reserves, so removing foliage impacts food production and root growth.
Recovering from Pruning
It’s important to remember that root reduction after pruning is usually temporary. Within 1 to 3 years, an appropriately pruned healthy tree will regenerate the lost roots and return to its prior vigor.
Trees have amazing regenerative capacities. As the canopy re-grows after pruning, photosynthesis increases, allowing more carbohydrates to be sent to the roots. This stimulates new root establishment.
Guidelines for Pruning to Minimize Root Impacts
Follow these tips to prune trees while minimizing reduction of roots:
- Prune lightly and gradually. Removing no more than 25% of live foliage at a time allows trees to recover better.
- Use crown thinning instead of crown reduction when possible. This has less impact on roots.
- Prune in late winter when trees are dormant and energy demands are lower.
- Avoid heavy pruning just before spring growth flush.
- Leave some branches with buds so new foliage can quickly regrow after pruning.
- Maintain tree health with proper watering, fertilization, and pest control after pruning.
Severe Pruning Effects
Drastic pruning of over 50% of the canopy can stunt root establishment for several years. Without enough foliage for photosynthesis, the tree struggles to produce and transport carbohydrates to roots.
Repeated heavy pruning year after year keeps trees stressed. Their root systems remain underdeveloped and unable to adequately anchor and support the tree. It becomes prone to uprooting and blowover in storms.
Special Case – Root Pruning
Root pruning refers to cutting back roots themselves, often to control size or create a shorter root system when transplanting.
This directly removes part of the tree’s root system and does reduce the overall root mass. However, new roots will generate from the remaining roots and root flare over time.
Does pruning reduce root growth? In the short term, heavy pruning can slow root development. But when done properly, pruning does not permanently hinder root growth. A healthy tree will regenerate its root system within a few years after pruning.
So while pruning might temporarily reduce root mass, it is an essential practice for maintaining tree health and form. By following some basic guidelines, trees can be pruned without any long-term negative impacts on their roots.
Frequency of Entities:
Crown reduction pruning: 4
Crown thinning pruning: 3
Root pruning: 2
Root growth: 15
Roots: 14
Pruning: 22
Tree: 28
How Does Root Pruning Impact the Roots?
Professionals should handle any root pruning, as one wrong cut can significantly damage the tree or destabilize it. Cutting trees in the right places can lead to strong new growth, but it’s easy to hurt the tree’s fibrous feeder roots, which it needs to stay healthy.
As professionals, we avoid root trimming unless it is absolutely essential. We also recommend never attempting this task if you do not have the proper expertise. There is a significant risk of killing the tree if you damage too many feeder roots. Damaging the main structural roots can result in the tree falling over.
How Does Pruning the Crown Affect the Roots?
When you trim the tree’s crown, it makes it upset, which makes it rush to replace the lost part of the canopy as soon as possible. As a result, the roots don’t grow during this stage. Improper crown trimming can, therefore, prevent the tree from setting down strong roots.
Any trimming of the crown is a risky proposition because it distresses the tree greatly. It makes the tree send out wiry branches so that its canopy can grow back as quickly as possible. While these can look untidy, it is unwise to trim these for at least a year.
[Expert Answers] Does Trimming Trees Prevent Root Growth?
FAQ
Does trimming a tree reduce root growth?
How to slow down root growth?
Will a tree root grow back if you cut the root?
What happens to roots after pruning?
Does pruning a tree stop root growth?
However, pruning a tree will not stop root growth if it is done in late winter or early spring when trees are dormant. But if you prune a tree during its active growing season, this will reduce root growth by up to 50%. However, pruning a tree will stop the root growth, but it does not kill the roots.
Why do trees need to be pruned?
Tree Transplantation: During the relocation of a tree, root pruning reduces stress on the tree and encourages fresh root growth in the new planting site. Damage Prevention: If tree roots are encroaching on buildings, pavements, or utility lines, root pruning redirects their growth, mitigating potential harm.
How does crown pruning affect a tree?
Crown pruning causes a tree to stop growing roots and quickly replace the lost leaves. Without enough leaves, the tree has less energy and hormones it needs to repair its wounds or grow roots. The tree pauses root growth and focuses its energy on growing new shoots and leaves as quickly as possible.
Do tree roots need to be pruned?
Roots are a critical part of a tree that maintains its health and stability. While sometimes roots need pruning, incorrect techniques can lead to the death or toppling of a tree. Therefore, root pruning should not be attempted without proper experience and knowledge. Read this guide to pruning tree roots to make well-informed decisions.
Does trimming a tree kill roots?
However, pruning a tree will stop the root growth, but it does not kill the roots. The roots still grow and can send out new shoots, leading to faster growth of the tree. The best you can do is remove some of the lower branches on your trees to slow down their growth rate. Does trimming a tree help it grow?
Should you prune a young tree or a mature tree?
A young tree will respond to root pruning much better than a mature tree. Young trees have a much smaller root diameter. A small root diameter means you aren’t making significant cuts. So, the tree doesn’t have to work as hard to remediate any cuts. Pruning large roots in mature trees can also affect the tree’s stability.