Why Not Topping
Why Topping & Lopping
Are Not Recommended Practice
The industry didn't decide topping and lopping were bad practice as a marketing exercise. AS 4373 exists because unmanaged reduction cuts produce documented, repeatable, negative outcomes. If a contractor tells you they'll "top the tree" and quote you a low price, they're offering something the tree pays for — and that you pay for again in 3–5 years.
1. Tree Stress
Removing more than about 25% of a tree's live canopy in a single operation strips more food-producing leaf area than the tree can regenerate before its energy reserves run out. The tree survives, but weakened — more susceptible to pests, drought, and secondary infection.
2. Weak Regrowth
Cuts made mid-branch (rather than at a lateral) produce a burst of epicormic shoots — many thin, fast-growing branches that emerge from the wounded area. These shoots are weakly attached to the parent wood and are structurally much more likely to fail in wind than the original branch was. Three years post-lopping, the tree looks bushy again — but it's more dangerous than before.
3. Decay Entry
Trees can compartmentalise small, correctly-placed wounds. Large stub cuts made at a random point on a branch can't be compartmentalised effectively — decay fungi enter the exposed wood and progressively rot the branch from within. You often can't see this from the outside for years.
4. Aesthetic Damage
A properly crown-reduced tree still looks like a tree — same natural shape, just smaller. A lopped tree looks like a set of stubs with regrowth clumps at each cut point. This affects both property value and how neighbours feel about the work, particularly for prominent street-facing trees.