Tree Topping: Why You Should Never Do It

Topping is the practice of cutting back large branches to stubs or lateral branches too small to take over the terminal role. It is sometimes called hat-racking, heading, or rounding over. Whatever you call it, every reputable arboriculture organization in the world considers it one of the most damaging things you can do to a tree. Yet it still happens constantly in Calgary.

What Topping Actually Does to a Tree

When you remove a large portion of the crown in one cut, you strip away 50 to 100 percent of the tree's leaf-producing capacity. Leaves are how a tree feeds itself through photosynthesis. Removing them forces the tree into a starvation response. To survive, it activates dormant buds along the remaining stubs and sends up a flush of fast, weak growth called watersprouts.

These watersprouts grow rapidly, sometimes several feet in a single season, but they are poorly attached to the parent branch. They originate from surface tissue rather than developing from within the branch the way natural branches do. This means they are structurally weak and far more likely to break in wind or under snow load than the original branches were.

It Creates More Danger, Not Less

Most people who top a tree do it because they think the tree has gotten too tall and poses a risk. The irony is that topping makes the tree more dangerous over time. Within a few years, the watersprout regrowth will reach the same height as the original canopy but with far weaker attachment points. You end up with a tree that is the same size but structurally compromised.

The large stub cuts also create entry points for decay organisms. As the stubs rot, the decay works its way into the main trunk, weakening the entire structure from the inside out. A topped tree is a ticking clock.

It Harms the Tree's Health

Beyond structural damage, topping causes severe physiological stress. The sudden loss of foliage triggers a survival response that depletes the tree's stored energy reserves. The tree becomes vulnerable to insects and diseases that a healthy tree could normally resist. Sun scald becomes a problem too. Interior branches that were previously shaded are suddenly exposed to direct sunlight, and the bark can crack and die.

Many topped trees never recover. They enter a slow decline that ends in death within five to ten years, sometimes sooner for species that do not tolerate heavy pruning, like birch and many conifers.

It Destroys the Tree's Appearance

A well-formed tree is one of the most beautiful features of any property. Topping destroys the natural shape permanently. The dense, bushy regrowth from stubs looks nothing like the original graceful branching pattern. Even with years of corrective pruning, a topped tree rarely regains its former shape. The aesthetic damage to your property is immediate and long-lasting.

What to Do Instead

If a tree is too tall, too wide, or encroaching on structures, there are proper alternatives that reduce size while preserving the tree's health and structure:

• Crown reduction: This technique shortens branches back to a lateral branch large enough to assume the terminal role, typically at least one-third the diameter of the cut branch. It reduces height while maintaining natural form.
• Crown thinning: Selectively removing interior branches opens up the canopy, reduces wind resistance, and lets more light through without changing the tree's overall height or shape.
• Crown raising: Removing lower branches provides clearance for structures, vehicles, or sight lines without affecting the upper canopy.
• Removal and replacement: If a tree has truly outgrown its space and no amount of pruning can solve the problem, it may be better to remove it and plant an appropriately sized species.

How to Spot a Bad Operator

Any tree company that suggests topping as a solution should be avoided. Certified arborists are trained to never recommend it. If someone knocks on your door offering to top your trees at a bargain price, that is a major red flag. Always ask for ISA certification and references before hiring anyone to work on your trees.