OLR Research Report

September 8, 2004




By: Paul Frisman, Associate Analyst

You asked (1) what constitutes tree trimming, (2) why anyone may remove a tree or branch, but only a commercial arborist may trim a tree, and (3) how to obtain an arborist license.


By law, arboriculture involves work done to improve a tree's condition. Only a commercial arborist, licensed by the Department of Environmental Protection (DEP), may perform such work. Branch or tree removal intended to protect power lines, improve sight lines, or other purposes not related to improving a tree's condition is not considered arboriculture, and need not be done by a commercial arborist. The law pertains only to commercial arboriculture. A homeowner may prune his own trees.

An individual interested in obtaining an arborist's license should apply to DEP. A test is required and there is a $25 application fee. We have attached additional information on the licensing process. The information also is available on the DEP web site.


By law, an arborist is someone who, for hire, improves the condition of fruit, shade or ornamental trees by feeding, fertilizing, pruning, trimming, or bracing them, by treating cavities, or other methods of improving tree conditions, or protects them from damage from insects or diseases, or cures these conditions by spraying or any other method (CGS 23-61a). An individual must have a DEP license to perform arboriculture, but the law exempts from this requirement people who improve or protect trees on their property or that of their employers (CGS 23-61b(a)).

According to a 1971 attorney general's opinion (attached), whether an arborist's services are required depends on the purpose of the pruning. Commercial pruning or tree removal done to provide a right of way, remove dangerous limbs, or improve sight lines does not require the services of a licensed arborist because it is not done to improve the tree's condition.