Commentary by Daren Mindham
Topping, whether it is called tipping, stubbing, heading-back, lopping or rounding-over, is the indiscriminate cutting of branches on a tree. It is a self-defeating practice not worth the expense. The results pose a danger from rot and weak re-growth. It is harmful to the tree. Many people believe it is the proper way to prune trees, but it is not.
Topping versus pruning: Topping is the excessive and arbitrary removal of all parts of the tree above and beyond a certain height with no regard to the structure or growth pattern of the tree. Pruning is the selective removal of certain limbs based on the structure and growth pattern of the tree. Pruning, when done correctly, is not harmful to the tree.
Tree topping myths:
The tree is too tall
This indicates poor species selection, improper tree placement or fear that the tree might be dangerous in storms.
Topping reduces the risk of storm damage
The reduction in height reduces risk temporarily, but as the tree re-grows it is structurally weaker and the risk becomes greater.
It has to be topped because of power lines
Tree and power line conflicts may be resolved by proper species selection, better placement or different pruning technique. Remember: Power line clearance benefits the lines, not the trees.
Problems caused by topping:
The balance between the roots and crown is destroyed. Removal of too many branches and leaves can starve trees. Without foliage, trees cannot make enough food to maintain growth and vigor.
Sunscald can occur. Bark tissues suddenly exposed to full sun may be burned and develop disease cankers.
Large stubs cannot wall off the cutting wound. Stubs are separated from food and water flow. As tissues die, wounds do not seal and decay may enter and spread to the trunk.
New growth is weak. New sprouts are attached to the surface of stubs rather than being anchored from within former limbs.
Topping can create a hazard. Storms do more damage because the new growth is weakly attached.
Topping disfigures trees. Topping alters a tree’s natural beauty and form.
Topping is only temporary. Trees will grow to their natural height. Rapid re-growth is nature’s way of recovering from disasters, and frequent topping will be required to keep a tree under control.
Alternatives to Topping:
Select the right tree and plant it in the right place. A tremendous selection of trees is available. One can be found that will grow to just the right size and to avoid power lines and other hazards.
Remove the tree and replace it. If removed, remember to follow the right tree in the right place guidelines.
Prune the tree properly. Proper pruning removes limbs where they are attached to a larger branch or the trunk. Selective removal of limbs reduces the wind resistance of the tree. It also allows some light to penetrate the crown. Proper pruning improves the shape and balance of the crown.
The practice of topping is not recommended by the City of Carmel. It can lead to tree decay, add to storm damage and disfigured trees. Proper pruning that thins the crown with cuts made at branch collars is the best practice for the long-term health of trees.
Daren Mindham is the urban forester for the City of Carmel. Learn more at carmelurbanforestry.com.