Bismarck City Arborists Say “Just Say No!” to Topping

BISMARCK, N.D. – Topping a tree consists of removing 50-100% of the tree canopy (top of the tree).   This is an extremely damaging practice as it causes weak branching structure and in some cases death of a tree.  Since at least 50% of the canopy is being pruned out, the tree needs to compensate for the lost leaves.   The tree will rapidly produce shoots that grow right below the pruned section.  Since these shoots are formed quickly and profusely, the attachment is not strong.  City Arborists have observed “topping” of trees being done on trees in the community and want citizens to be aware of the hazards of this practice. 

The wound left from topping can become a hazard of its own because of potential decay/rot issues.  Since there are so many large stubs left behind from topping, the tree is not likely able to callus over all of the open wounds.  These wounds leave an open path for insects, diseases, and decay to form in the tree.  Branch failure is prone to happen due to the added weight from the shoots growing off of a weakening branch stub.

The bark of the topped tree can also be affected.   When 50% or more of the leaves are lost during topping, trees can actually get sunburned due to the loss of shade.  This damages the inner tissues of the tree causing the bark to split and cankers to form.  These cankers ultimately destroy a tree by causing loss of structural integrity.

The City of Bismarck Forestry Department maintains a list of Licensed Arborists in the City of Bismarck and encourages citizens to use a Licensed Arborist for tree trimming.  Please visit www.bismarck.org/forestry.  Click on Pruning and Licensed Commercial Arborists.  For more information please call 701-355-1733.