The Dangers of Tree Topping

Whether it’s a tree that’s been sheared to allow clearance for power lines, or a poor crepe myrtle that’s been “murdered,” we’ve all seen the unfortunate realities of tree topping. But what’s so bad about it? And why, when the practice is pretty universally looked down on in the arboricultural world, is it still happening? 

​What is Tree Topping?

Tree topping, also known as heading, stubbing, or dehorning, is the practice of drastically removing some or all of the large branches of a mature tree. Though "top" is in the name, the removed branches can come from any part of the canopy. They may be cut all the way back to the base, or they may just be chopped off at whatever point is needed to achieve a particular goal (like clearing way for utilities, removing visual obstruction, or even just reducing overall height to a certain range).  

​Why is Tree Topping Bad?

​Obviously, trees need their leaves to survive. But you might not realize that, in order for a tree to thrive, it actually maintains a certain crown-to-root ratio designed to ensure it obtains enough nutrients both from photosynthesis and from the ground to support itself. The exact ratio will depend on the species, age, and size of the tree, but every tree has one. 

​Tree topping drastically upsets that ratio by removing a significant portion of the crown, thereby removing a significant portion of how the tree obtains nutrients. Not to mention its reserves for harder times!

With large sections of foliage removed, the tree will attempt to regrow that foliage through new growth shoots. These smaller, upright “water sprouts” are delicate and more susceptible to disease, which can easily spread to the rest of the tree. They also grow densely clustered together, disrupting the tree’s natural growth pattern. This can be unsightly, of course, but also creates an imbalance in distribution that can lead to structural failure later in the tree’s life.

On top of decimating a tree’s ability to gather nutrients, tree topping also exposes the tree to a variety of potentially devastating circumstances. The main problem is the wounds left behind from each cut. Normally, the tree would close, callus, or otherwise seal off the injury to prevent things like insects, fungi, and other decay from setting in. But when a large branch is fully cut off, the tree will no longer send nutrients to that branch, since there’s no foliage to support. Without those nutrients, the wound won’t close, and the injury will remain vulnerable to pests and decay that can easily spread to the rest of the tree. 

​Another concern is sun damage. When the normal canopy is removed, the remaining branches and trunk are left without protection from the sun and may get the tree equivalent of sunburnt!

​If It’s So Bad… Why Is It Still Happening?

As we mentioned, tree topping usually happens when trees grow too close to power lines or other utilities. In these kinds of public spaces, cost-effectiveness is usually prioritized over any individual tree’s wellbeing. Selective pruning, while better for the tree, is often more difficult and time-intensive (and therefore more expensive) than just using a pole saw to hack away the offending branches. Fully removing the tree can also be more time-intensive and expensive, which is why the topping option is chosen. 

Trees are also topped in situations where they are obstructing a view or casting shade where shade is not wanted. In such cases, selective pruning wouldn’t necessarily solve the problem the way that topping does, and so it won’t be chosen. 

Most homeowners that choose to have a tree topped are either trying to get some sun on their garden, or are worried that the tree in question is too tall and poses a threat to their home. They likely don’t even realize that topping is such a bad thing! That’s why we always recommend having your tree work needs reviewed by a Certified Arborist – someone who can warn you of the dangers, and recommend practices that can help you achieve your goals without hurting your trees! 

Have a tree you’d like pruned? Contact Classic City Arborists today to schedule a free quote!

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Author

Emily Casuccio is sister and sister-in-law to Rebekah and Scott Rushing, and has worked with Classic City Arborists for the last 5 years. In addition to handling administrative tasks and customer communication (she’s the voice you’ll hear on the phone!), Emily is an experienced copywriter, editor, and storyboard consultant. To learn more about her, read samples of her work, or contact her, visit her online portfolio.

Sources:
International Society  of Arboriculture