Understanding Tree Topping and Why It’s Harmful to Trees

As responsible property owners, it’s essential to understand the best practices for maintaining the trees in our unique New Zealand. One common practice, known as tree topping, is commonly misguided and can be harmful to your trees. In this article, we will delve into why tree topping is harmful, especially in the NZ context, and highlight sustainable alternatives for managing tree growth.


What Is Tree Topping?

Tree topping, also known as ‘heading,’ ‘tipping,’ or ’rounding over,’ involves indiscriminately cutting back tree branches to stubs or lateral branches. Resulting in the remaining branches being too weak or small to handle the job that the top part of the tree usually does. They can’t serve as the main growth point, and this can lead to problems with the tree’s health and stability. This process is typically aimed at reducing the size of the tree, whether for aesthetic reasons or to lessen the perceived risk of the tree falling.

However, this extreme form of pruning is widely considered harmful and counterproductive. It can lead to a variety of health issues for the tree and may actually create more problems than it solves.

Problems Tree Topping can cause

  1. Increased Vulnerability to Diseases and Pests: The large, open wounds left by topping can make the tree more susceptible to infections and insect infestations.

  2. Unattractive Appearance: Topping can lead to a misshapen and aesthetically unpleasing appearance, with weak, spindly branches growing where the tree was cut.

  3. Decreased Property Value: Unhealthy and unattractive trees can lower the aesthetic appeal of a landscape, potentially reducing property values.

  4. Long-term Health Issues: The stress and damage caused by topping can lead to long-term health issues for the tree, potentially shortening its lifespan.

  5. Increased Maintenance Costs: Trees that have been topped usually require more frequent care and maintenance, leading to increased costs over time.

  6. Sunburn: By removing the tree’s leaf-bearing crown, topping can expose the remaining branches and trunk to more direct sunlight, possibly leading to sunburn and further damage to the tree’s bark and underlying tissues.

  7. Potential Liability: Weakly attached branches are more likely to break, possibly causing injury or damage to property, which might result in legal liability for the property owner.

Topping Stresses Trees

Trees need a substantial leaf surface area to produce the food required for growth and overall health. Topping, which removes 50-100% of a tree’s leaf-bearing crown, significantly impairs its ability to photosynthesize, leading to considerable stress.

Furthermore, topping cuts are often made without regard to the tree’s natural structure, resulting in weakly attached new branches and a host of other problems such as:

Rather than enhancing the safety and stability of the tree’s branches, topping can actually make the tree more dangerous in the long run.

topping stresses trees

Why Is Topping Bad for Your Trees?

Topping can lead to a variety of health issues for trees. By removing a substantial portion of a tree’s crown, topping essentially starves the tree, triggering a survival response. This causes the tree to activate latent buds on lateral branches, forcing rapid growth of multiple shoots below each cut. Unfortunately, these new shoots are weakly attached and prone to breaking, rendering the tree more hazardous.

In addition to leaving large wounds on the main branches, topping exposes the tree to diseases and insect infestations. This practice also bypasses the tree’s natural defense mechanisms, such as growth chemicals found in the branch collars. As a result, the remaining branches become vulnerable, and the overall health of the tree is further compromised.

The Destructive Impact of Topping Trees

Topping trees creates multiple severe wounds by indiscriminately cutting back branches. Each cut not only exposes the tree’s delicate wood tissues but also provides an entry point for decay organisms. These open wounds lead to rapid deterioration of the exposed wood, weakening the tree’s overall structure and making it more prone to diseases and pests. Rather than preserving the health of the tree, topping actually undermines its vitality and accelerates its decline. For those seeking healthy trees, proper structural pruning is a far better option. This method aligns with the tree’s natural growth patterns and minimises the risk of severe wounds, thereby ensuring both longevity and aesthetic appeal.

Creates Bigger Problems

While topping a tree might appear to be a quick fix for overgrown branches, it often leads to more significant problems. Besides the issues previously mentioned, trees that have been topped tend to grow back faster and more densely. This vigorous regrowth can quickly restore the tree to its original height, but with a thicker canopy, thereby nullifying the initial purpose of topping.

Furthermore, topped trees often lose their natural beauty, with large branches cut awkwardly and the tree’s inherent structure and form disfigured. This unattractive appearance can even diminish the property value if applied to several trees on the premises. Ultimately, topping can drastically reduce a tree’s lifespan, making it an ill-advised approach to tree maintenance.


The Hidden Costs and Consequences of Tree Topping

  • More Frequent Care Required:

    • Topped trees grow back vigorously but new branches are weakly attached.

    • This regrowth needs more regular pruning, increasing the frequency of maintenance.

  • Increased Maintenance Costs:

    • The regular care and attention required for topped trees can lead to a rise in overall maintenance costs.

    • Specialised equipment and expertise might be needed to deal with the abnormal growth patterns.

  • Liability Risks:

    • Weak branches can break and pose risks to nearby property.

    • Property owners might face significant liability costs if a topped tree causes damage or injury.

  • Expensive Removal and Replacement:

    • If topping leads to the decline or death of the tree, removal and replacement can be costly.

    • Properly removing a large, unstable tree requires skilled labour and can be expensive.

  • Impact on Property Value:

    • The appearance of topped trees can diminish the aesthetic appeal of the property.

    • This could lead to a decrease in property value, particularly if multiple trees are affected.

  • Reduction in Tree’s Lifespan:

    • Topping often leads to long-term health problems for the tree.

    • This can drastically shorten its lifespan, requiring earlier replacement and additional costs.

  • Environmentally Unfriendly:

    • Topping disrupts the tree’s ability to absorb carbon and provide habitat for wildlife.

    • It can also affect soil health and water retention in the surrounding landscape.

  • Alternative: Proper, Regular Tree Care:

    • Proper pruning techniques that respect the tree’s natural growth patterns are more effective.

    • Regular, thoughtful care can ensure the tree’s longevity, aesthetic appeal, and health, often at a lower overall cost.

Alternatives To Tree Topping

Instead of resorting to the extensive wounding that comes with tree topping, it’s wise to consider more tree-friendly alternatives. One such method is thinning, which involves selectively removing branches to increase light penetration and air movement through the tree. This not only reduces the tree’s wind resistance but also enhances its health and appearance, all while preserving its natural shape.

If you’re dealing with trees that have grown too tall, you might consider a technique known as crown reduction. This method reduces the height or spread of the tree’s crown by carefully pruning the leading branches and terminals to lateral branches that are robust enough to take on the main growing roles. The result helps maintain the tree’s natural form and structural integrity.

Keep in mind that regular pruning during a tree’s early years is the optimal way to ensure health and manageability. If you’re uncertain about the proper techniques, don’t hesitate to consult a professional arborist.

Understanding the detrimental effects of tree topping represents a crucial step towards more responsible and effective tree management. Armed with this knowledge, you can promote the well-being of your trees and enhance the overall appeal and value of your property.

Picture of Dylan Heath

Dylan Heath

Dylan Heath is a fully qualified arborist with over 13 years of experience working in both the private and local council sectors. He comes with a wealth of knowledge, skill and passion for arboriculture.