Last week, in a New Jersey advertising circular, I saw an ad for a tree service that read, “Over 25 Years Experience! Removals, Pruning, Stump Grinding, Aerial Lift Equipment.”

While experience is helpful in many cases, of the services offered, only pruning directly involves tree healthcare. And, in the case of tree healthcare, experience is not as important as knowledge. I am sure George Washington’s doctors were experienced, but that did not stop them from removing more than 40 ounces of his blood to treat what may have been as insignificant as a severe head cold. So, experience is not directly correlated with accuracy.

Experience can provide safety and efficiency for the workers and the worksite, but what about the tree?

Two weeks ago, I noticed a very experienced tree worker working on a beautiful oak tree in Clarks Green. I wondered if he had knowledge to go with his experience, so I looked at the tree after he was finished working. I did not have to even scan the crown of the tree to find a significant problem. Eight feet up into the tree, this experienced worker left a stub cut. In other words, he had missed the proper pruning location by 18 inches.

Was this miss insignificant? Perhaps, since it is an oak tree, but consider this — he had cut the branch eighteen inches from the area of intense meristem cells known as the “branch bark collar.” Meristem cells can quickly react to trauma and, at the branch collar, after a pruning cut they begin forming wound wood to close the opening. Wound wood is the strongest wood on a tree and, as it closes the wound, it provides the most effective barrier against decay.

In the case of a stub cut, it is too far from the concentration of meristem cells to ever close the wound. The tree is left with two options: stub dieback or watersprouts. Both options are bad for the tree and the homeowner. In the case of the stub dying back, the decaying stub remains on the tree as a permanent conduit for decay to enter the trunk as well as for disease and insect infestation. Then, when the stub finally succumbs, the homeowner can only hope it is not on his or her head. In the case of watersprouts, often four or five adventitious sprouts will emerge near the improper pruning cut. In time, these unsightly twigs become a congregation of limbs supported by a decaying stub. Add gravity, and this is a recipe for disaster.

More knowledgeable pruning might have cost more up front, but fixing or replacing this tree in time will cost even more.

Joshua Arp is an ISA-certified Municipal Specialist, a Clarks Summit Tree Commissioner and an operator of a landscape maintenance business. He can be reached at