While tree pruning is probably the most commonly performed tree care service, if done incorrectly it can have severe negative long term impact on tree health and safety. For a detailed explanation of what correct pruning is and isn’t, see my “Pruning Tips” page.
One quick way to determine if you are dealing with a professional is by the language they use. Dr. Alex Shigo, the father of modern arboriculture, used to emphatically make this point all the time. And when it comes to removing branches from trees, professionals refer to this as “pruning”. “Trimming” is for hair; “sculpting” is for rock. May seem like a minor point, but this “test” is actually pretty accurate, at least in Austin. Sculpting in particular is a term used by some yahoos that like to strip all the foliage out of the interior of tree- BAD idea! Again, see my pruning tips page. Ask to see the work of anyone you’re thinking of hiring. If the canopy of every tree they prune looks like an umbrella, don’t hire them!!!
Knowing the term “branch collar” can be another indicator of how knowledgeable a tree care provider is or isn’t. Of course beware of posers who just throw around esoteric terms without having a clue what they mean. Someone who really knows what a branch collar is can explain it to you in a way that makes sense. Again, see my “Pruning tips” page. ONLY hire tree care companies that make ONLY branch collar cuts.
The pictures below show the proper removal of the typical branch at its collar. However, it is critical to understand that the shape and angle of the branch affect the final cut. Not all branch collar cuts look exactly like the one below right. The point is that most cuts that are either flush against the trunk or which leave a “stub” are incorrect. The flush ones can be quite injurious.