One of the more persistent myths among the green industries in Connecticut concerns the existence of the so-called ‘fifteen foot rule’. Like most myths, this one has several variations. In its most common version, this rule says that, as long as one is not doing work that is more than 15 feet off of the ground, one does not need an arborist license to work on a tree. In other words, pruning, spraying or cabling a tree is fine without a license, as long as one stays below 15 feet.

In fact, as anyone with an arborist license knows, there is no such thing as a fifteen foot rule. The law states it very clearly – one may not "advertise, solicit or contract" to do arboriculture without a license. As defined in the statute, ‘arboriculture’ means fertilizing, pruning, trimming, bracing, treating cavities, controlling pests, and so on. The law makes no exceptions for trees of various heights, nor for specific parts of the tree, such as that part below fifteen feet in height. From that basis, the fifteen foot rule is pure fiction.

However, there is one interpretation of licensing policy by DEP that somewhat relates to the so-called fifteen foot rule. When establishing its pesticide licensing categories in the early 1970’s (in response to FIFRA and well after the original Tree Expert Law, passed in 1919), DEP recognized that it faced a dilemna. While the established Arborist Law gave authority for treating trees to licensed arborists, it was not clear what should be done in cases where tree species were nearly shrub-like in form or otherwise not being maintained as 'trees'. Specifically, should a landscaper with an ornamental and turf pesticide supervisory license be required to get an arborist license in order to apply pesticides to a hemlock hedge or a small flowering tree?

DEP, for the sake of simplicity, determined that the second license was not necessary in these cases. To make this informal policy understandable, they set the arbitrary guideline of a plant height of 15 feet as the determining factor as to which license applied, recognizing that this interpretation is both informal and arbitrary, and that common sense needs to prevail in field applications. This Department continues to use this as an informal guideline governing pesticide use. This guideline does not exist anywhere except as a guideline - it is not in the regulations or in statute.

The so-called fifteen foot rule may or may not have grown from a misunderstanding of this working arrangement regarding two supervisory licenses. Regardless of its history, it is off base. For one thing, until 1998, DEP never had to consider pruning with regards to any of the licenses it administers, arborist or otherwise. More importantly, a guideline that is convenient and, for the most part, sensible with regards to the use of pesticides on smaller woody landscape plants cannot be used to justify unqualified and often damaging activities on these and other woody plants.

Besides encouraging the acceptability of poor work on smaller ornamentals and in the lower crowns of larger shade trees, the so called fifteen foot rule also has the insidious effect of encouraging the damage of young trees in the landscape, with the potential to create problems for years ahead. Let me explain. One of the most important periods of time for pruning a tree is when that tree is young – from shortly after planting until it begins to approach its mature height. During that stage, young trees are full of vitality, and the great abundance of living tissue within the tree responds rapidly, especially to pruning cuts. At the same time, this young tree is developing the structure that will be the basic form of the mature tree.

This is where the hand of a licensed professional – of someone who knows what he or she is doing – is so important. At this stage, the tree may go down many different paths in its structural development. It may develop properly spaced scaffold branches, each with strong crotches and a good branch angle, or it may develop multiple leaders and poor crotches full of included bark. In other words, depending upon who has a hand in this tree, it may develop into a mature tree that is strong and gives decades of beauty with minimal maintenance requirements, or it may become a hazard and an eyesore on the landscape.

There are those who see arborists only as crafts-people, notable for their skill in the use of ropes and their ability to move around in a tree canopy, and who can be trusted to make proper pruning cuts. If this is all someone sees in an arborist, they sell the profession short. Arboriculture is much more than a craft; it is a profession. Arboriculture involves an understanding of the whole tree – of its health, of how it grows, of what affects the tree and of how we can influence this tree in its health and growth. It is the whole package. It is not limited by tree size or location within the tree.