For years, tree topping was considered the easiest and cheapest way to make mature trees safer and reduce their size. Today, tree researchers have proven that both of these assumptions are false. "Millions of trees have been hacked with little or no consideration to their health and structural integrity," says Tchukki Andersen, staff arborist with TCIA. According to TCIA, many of these trees eventually die as a result of the damage. Others eventually become unsafe, leading to dangerous limb breakage or whole tree failure years after the topping was done.

TCIA and the American National Standards Institute A300 pruning standards consider topping to be an unacceptable pruning practice. "Tree service companies that follow industry standards will refuse to top your tree," notes Andersen.

What is topping?

Topping is a non-standard pruning procedure where larger trees are severely cut back to a pre-determined size. It is also known as hat-racking or de-horning. Topping was a traditional pruning method that was considered acceptable long ago. The following is up-to-date information about topping:

Topping trees:

• leaves large exposed wounds, which can pre-dispose the tree to infestation or other future health problems;
• ruins tree structure;
• removes too much foliage, disrupting the tree's energy storage;
• stimulates vigorous new growth, which is prone to breakage;
• increases tree maintenance costs; and,
• destroys the tree's appearance and value.

Why trees are topped?

Some consumers top trees out of tradition, since that is the way it was done in the past. Other consumers mistakenly believe that topping a tree reduces its size and lowers the maintenance cost. However, published research has proven that many species of tree that are topped actually grow more over a five-year period when compared to trees that were pruned correctly.