Tree topping is a practice where major limbs and branches are cut back to a certain height, leaving stubs. It’s done primarily to reduce the height of the tree because the owner is afraid it will get too big and fall, or to keep it out of utility lines. If you are tempted to top a tree, take a drive through some neighborhoods right now while the leaves are off the trees and look for trees that have been topped over the last few years. You will likely see badly decayed major limbs. Let me count the reasons topping is bad.
Topping hurts tree health: A huge imbalance between the root system and the canopy is created, which will starve a tree, leaving it weak and stressed until it grows back its foliage and supporting branch structure. Stressed trees are more susceptible to insect and disease problems.
Topping is a temporary fix. Trees are forced to grow back their original canopy or starve as mentioned. Rapid re-growth is nature’s way of recovering from damage, and frequent topping will be required to keep a tree controlled to a desired height.
Sunscald can occur: Formerly shaded bark tissue suddenly exposed to full sun may sunburn and develop disease cankers.
Topping causes decay: Trees do not heal at stub cuts. They always try to heal at branch intersections, a protective action called compartmentalization. So stub wood created by topping will die back to its intersection with the tree, but unfortunately remains in place and doesn’t allow the wound to heal over at that junction. The result is decay entering the tree through the decaying stub, which eventually spreads into the tree truck.
New growth is weak: Growth that comes in after topping a tree forms near the top of the stub cut rather than being anchored from within former limbs. When the stub begins to decay (and it will), the new sprouts are vulnerable to breakage.
Topping can create a hazard: Storms do more damage because the new growth is weakly attached as mentioned earlier
Topping disfigures trees. Topping alters the tree’s natural beauty and form. Again, take a look at topped trees in wintertime……uuuuugly.
Tree topping shortens lifespan: Because of all of the above.
There are alternatives to tree topping that will allow a reduction in height without endangering the tree, so contact your local forestry agency or county extension service for more information.