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Tree Topping Increases Safety Risks and Expense Say Tree Care Experts

TCIA Cites A300 Standards as Resource for Proper Pruning Techniques

New York, Mar 21, 2008

“Topping,” “hat-racking” and “de-horning” – all names for a non-standard pruning procedure that severely cuts back large trees to a predetermined size – has long been considered an easy and inexpensive way to manage the size and improve the safety of mature trees. Researchers, however, are cautioning that topping can increase safety risks and result in greater expense for the consumer . . . not greater savings.

A recent statement issued by the Tree Care Industry Association (TCIA), a professional resource on trees and arboriculture, identifies that topping trees:

  • leaves large exposed wounds that can become infested;
  • 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 a tree’s appearance and value.

Many trees die as a result of the damage caused by this drastic pruning technique; others eventually become unsafe due to dangerous limb breakage or whole tree failure that occurs years after the cuts were done. The risks arise because topping removes too much foliage, upsetting the delicate foliage-to-root ratio each tree tries to naturally maintain. The entire tree can fall due to root dieback.

Topping also means that large cuts are made at locations where a tree has no natural defense against the wood-eating insects and decay organisms that can quickly destroy it. Limbs weakened by decay may be unable to handle the weight of rapid re-growth, leaving new branches susceptible to breakage and falling. Published research has proven that topped trees grow more over a five-year period than do trees that were pruned correctly.

“Millions of trees have been hacked with little or no consideration to their health and structural integrity,” says Bob Rouse, TCIA’s director of accreditation. ”Trees that survive topping may eventually become a bigger safety hazard than they were prior to the cutbacks.”

TCIA’s recommendations against tree topping, along with guidelines for more acceptable pruning practices, are noted in the A300 series of American National Standards for tree care operations (see specific reference in ANSI/A300 – Part 1: 2001, section 5.5.7). The standards were developed by TCIA, administrator of the A300 committee, and approved by the American National Standards Institute (ANSI).

“Tree care professionals that follow industry standards will refuse to top your tree,” said Rouse. “Topping is a form of consumer fraud. Customers need to specify that corrective pruning be carried out in accordance with the appropriate ANSI A300 standards.”

Rouse suggests that consumers ask tree care services to define exactly what work they plan to do on a written proposal, thus avoiding any misunderstanding or surprises. The service provider can be requested to state on its proposal that all pruning will be done according to specifications contained in the ANSI A300 standards.

TCIA provides a free, online database of professional tree care service providers on its website. The resource contains contact information for the more than 2,000 TCIA members and accredited tree care companies that recognize stringent safety and performance standards, including the ANSI/A300 pruning standards. Additional tree care information is available at

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