How much can you safely prune from a tree? As a general rule, it is better to remove only as much live growth as necessary to achieve a specific pruning objective. For many established trees, removing around 10–20% of the live canopy in a single pruning session is a commonly used guideline, although the appropriate amount varies considerably depending on the tree species, age, health, structure, season and type of pruning being carried out.
Pruning more than necessary can place stress on a tree, reduce its ability to produce energy and encourage vigorous regrowth. Large or mature trees should be assessed by a qualified arborist before significant pruning is undertaken.
Why Does the Amount of Pruning Matter?
A tree’s leaves are essential to its health. They capture sunlight and use it to produce the energy the tree needs to grow and maintain itself.
When large amounts of live foliage are removed, the tree has fewer leaves available to produce that energy.
Heavy pruning can therefore:
- Reduce the tree’s ability to produce energy
- Cause stress
- Encourage vigorous regrowth
- Affect the tree’s natural shape
- Expose branches and stems to increased sunlight
- Create larger pruning wounds
- Alter the tree’s natural structure
- Increase the amount of future maintenance required
This is why professional tree pruning isn’t simply about removing as many branches as possible.
The goal is to remove the right branches for the right reason.
Is 10–20% a Safe Amount to Prune?
The often-used 10–20% guideline can be a useful starting point, but it should not be treated as a universal rule.
Some trees may tolerate more pruning than others, while young, stressed, declining or recently transplanted trees may require a more conservative approach.
The amount that can safely be removed depends on factors including:
- Tree species
- Tree age
- Tree health
- Tree structure
- Previous pruning
- Time of year
- Type of pruning
- Size and position of the branches
- Reason for the pruning
- Growing conditions
A qualified arborist should consider the individual tree rather than simply applying a percentage.
What Happens If You Prune Too Much?
Removing too much of a tree’s canopy can have consequences.
Stress and reduced energy production
The tree has fewer leaves available for photosynthesis, which can reduce the energy available for growth and maintenance.
Excessive regrowth
A heavily pruned tree may respond by producing large numbers of new shoots. These shoots can grow rapidly and may be poorly attached compared with naturally developed branches.
Changes to the tree’s structure
Removing major branches can change how weight is distributed throughout the canopy. Poorly planned pruning can therefore affect the tree’s natural structure.
Large pruning wounds
Removing large branches creates larger wounds. Trees do not heal wounds in the same way people do; instead, they respond by compartmentalising damaged tissue and growing new tissue around it.
Larger cuts can take longer for the tree to compartmentalise and may provide opportunities for decay organisms to enter.
Can You Remove More From a Young Tree?
Young trees can sometimes tolerate more selective pruning than mature trees, particularly when the objective is to develop good structure.
However, this doesn’t mean that a young tree should be heavily pruned.
Structural pruning should be carried out gradually, with the aim of developing strong branch architecture as the tree grows.
For example, an arborist may identify and remove competing leaders or poorly positioned branches while leaving the majority of the canopy intact.
Early structural pruning can help prevent the need for larger corrective cuts when the tree is mature.
What About Mature Trees?
Mature trees generally require a more conservative approach.
Large branches are a significant part of the tree’s established structure, and removing them can have a much greater impact than pruning a young tree.
With mature trees, the focus should generally be on selective pruning rather than major canopy removal.
An arborist may recommend removing deadwood, crossing branches, weakly attached branches or selected growth that is interfering with structures.
How Much Can Be Removed During Tree Reduction?
Tree reduction is different from routine pruning.
The purpose of tree reduction is to reduce the overall size or spread of the canopy while maintaining the tree’s natural form and structure.
A proper reduction involves selecting appropriate branches and shortening them back to suitable lateral branches.
Simply cutting the top or sides of a tree is not the same as professional tree reduction.
The amount that can be reduced depends heavily on the species, structure and health of the individual tree. In some cases, only a modest reduction will be appropriate.
If a tree is significantly too large for its location, an arborist may also need to consider whether reduction is a suitable long-term solution.
What Is Tree Topping and Why Is It Different?
Tree topping involves cutting branches back to arbitrary points, often leaving large stubs.
It is very different from properly planned tree reduction.
Topping can:
- Remove a large percentage of the tree’s foliage
- Create large wounds
- Produce vigorous regrowth
- Damage the natural shape of the tree
- Create poorly attached new shoots
- Increase future maintenance requirements
If a tree needs to be made smaller, a qualified arborist can assess whether reduction or another pruning method is appropriate.
Does the Tree Species Matter?
Yes.
Different tree species respond differently to pruning.
Some trees tolerate regular pruning well, while others can respond poorly to heavy pruning or large cuts. The natural growth habit of the species also affects how and where branches should be removed.
This is particularly important in Hobart and Southern Tasmania, where gardens contain a mixture of native Australian species, introduced trees and ornamental varieties.
An arborist should identify the tree and consider its characteristics before deciding how much to remove.
Does the Tree’s Health Affect How Much You Can Prune?
Absolutely.
A healthy tree may be able to tolerate appropriate pruning better than a tree that is already under stress.
If a tree is:
- Drought stressed
- Diseased
- Damaged
- Declining
- Recently transplanted
- Structurally compromised
heavy pruning may place additional stress on the tree.
In these situations, an assessment should be carried out before significant pruning is undertaken.
What If a Tree Has Already Been Heavily Pruned?
If a tree has previously been over-pruned, it may be tempting to cut it again to tidy up the resulting regrowth.
This can sometimes make the problem worse.
An arborist can assess the existing structure and determine how the tree is responding. In some cases, the best approach is to allow the tree time to recover before carrying out further corrective pruning.
How Does an Arborist Decide How Much to Prune?
A professional assessment looks at the whole tree rather than just the branches that are easiest to reach.
An arborist may consider:
- Why the tree needs pruning
- The species and growth characteristics
- The tree’s age and size
- Overall health
- Branch structure
- Previous pruning
- The surrounding property
- Potential hazards
- The desired outcome
- How the tree is likely to respond
This helps determine which branches should be removed and how much live growth can reasonably be taken from the canopy.
Should You Prune More to Avoid Having to Do It Again?
Generally, no.
It can be tempting to remove extra branches because the tree will eventually grow back. However, heavy pruning isn’t necessarily a good way to reduce future maintenance.
A better approach is usually to make appropriate, selective cuts that achieve the required result while preserving as much healthy canopy and natural structure as possible.
Regular inspection and smaller amounts of appropriate pruning can often be preferable to allowing problems to develop and then carrying out major corrective work.
Can You Prune a Tree Yourself?
Small, accessible trees may be suitable for basic pruning if you understand the species and proper pruning techniques.
However, larger trees present additional risks.
Large branches can be extremely heavy and unpredictable when cut. Working from ladders or at height also introduces significant safety hazards.
Professional equipment and experience are particularly important when trees are close to:
- Houses
- Roads
- Vehicles
- Fences
- Power lines
- Other structures
For significant pruning or large trees, it is safer to have the work assessed and carried out by a qualified arborist.
When Should You Call an Arborist?
Consider getting professional advice if you’re unsure how much to remove, particularly when:
- The tree is large or mature
- Major branches need to be removed
- The tree has already been heavily pruned
- The tree is diseased or declining
- There are large dead branches
- The tree is close to a building
- Branches are near power lines
- You want to significantly reduce the canopy
- The tree has structural problems
- You’re unsure whether pruning is actually necessary
A professional assessment can help determine the appropriate pruning method and avoid removing more of the tree than necessary.
Frequently Asked Questions
What percentage of a tree can you safely prune?
A commonly used guideline is to remove around 10–20% of the live canopy during a pruning session, but there is no single percentage that is safe for every tree. Species, age, health, structure and the type of pruning all need to be considered.
Can you prune 30% of a tree?
Removing 30% of the live canopy may be excessive for some trees, particularly mature or stressed trees. In some circumstances, more substantial pruning may be appropriate, but this should be based on the individual tree and the reason for pruning rather than a fixed percentage.
Can you cut half of a tree?
Removing half of a tree’s live canopy is generally a major intervention and can cause significant stress and structural problems. If a tree needs to be substantially reduced, an arborist should assess whether the proposed reduction is appropriate or whether another solution is required.
How much can you reduce a tree?
The amount a tree can be reduced depends on its species, health, structure, size and location. A proper reduction should maintain the tree’s natural form rather than involve arbitrary cuts to the top or sides.
Does pruning hurt trees?
Appropriate pruning should not unnecessarily harm a healthy tree. However, excessive pruning, incorrect cuts and the removal of large amounts of live growth can cause stress and structural problems.
Is it better to prune a little every year?
Not necessarily. Trees should not be pruned simply because a year has passed. Pruning should have a clear purpose. Some trees may benefit from periodic structural maintenance, while others may need little intervention.
Professional Tree Pruning and Tree Reduction in Hobart
Knowing how much to remove is only part of good tree pruning. Knowing which branches to remove, where to make the cuts and how the tree is likely to respond is just as important.
Matthew Clements Tree Service provides professional tree pruning, tree reduction and tree shaping throughout Hobart and Southern Tasmania.
Our qualified and insured arborists can assess your trees and recommend an appropriate pruning approach based on the tree’s condition, structure, location and your requirements.
If you’re unsure how much of your tree should be removed, it’s worth getting professional advice before picking up the saw.
