A Plea for Proper Pruning

March 1, 2024 · 4 minute read
A Plea for Proper Pruning

I was running errands at Willow Lawn recently when I noticed a jagged cut on a Crape Myrtle right next to my parking spot. Having been in my work truck I had the momentary fear of being associated with this atrocious pruning practice, but I continued to inspect it unfettered, drawn in by the ‘white eye’ of a recent cut. The angle of the cut started close to where a proper cut could have been made but then dug into the stem at a harsh angle. Presumably, the tree cutter caught their mistake and started again from the top of the limb to meet the first cut creating a ‘v’ shape into the stem. This was careless work that anybody could recognize as such. The tree looked bad, dare I say mangled by this poor cut and many others. I desperately tried to find a proper cut that may have happened, just by sheer accident if nothing else, to no avail. 

I took some pictures and decided it was time to talk about the importance of a proper pruning cut and how one might achieve it. Once you learn where to make a cut, when to make it, and why to make it there, the ‘how’ is just practice and experience. Trying to find where to make the cut takes some knowledge of tree anatomy, properly identifying the branch bark ridge, and finding the collar of the limb. If you can find a dead limb on a tree you’re about to work on, some species make it very obvious where the collar ends when they start the process of shedding the limb, so you can completely avoid making a larger cut than necessary. This is how the tree tells us where the process of compartmentalization ends and what part of the tree is ready to be removed. 

Before you ever pick up a saw or cutting implement, you should make sure it’s sharp and you know how to properly use it. A sharp saw will leave a cleaner cut, and with small-diameter wood, you ought to consider a small saw or hand snips. Please wear the proper PPE and start with something small, no more than an inch or so in diameter. Careful of the time of year as the limbs may be heavier with water and leaves, and it may be more prone to ripping the bark in the springtime as the sap is heavily flowing. Please don’t do this on a ladder, make sure you have proper footing to brace the limb. Use the rule of thumb that’s generally around thirds, which is you should avoid cutting anything more than ⅓ of a branch, back to a secondary limb no smaller than ⅓ of the original branch’s diameter. If that’s unclear, I’d advise doing some further reading, with your 1st assignment being Pruning: Best Management Practices, the companion publication to the ANSI (arborist’s bible).

When you are ready to cut, you can start with the 3-cut step process of pruning a branch, which starts with a cut to the underside of a branch, a few inches out from the union of the branch, to prevent a tear out. You can then make a second follow-through cut from the top of the limb, right above or slightly out a few inches on the limb (depending on the diameter of the limb, you can go even further out). Once the majority of the limb is free you can make the final 3rd cut. Your finishing cut is just outside the collar of the union to allow for the tree to properly ‘heal,’ or rather seal the wound. The collar is identified by the swelling in the branch that varies with the different species you may encounter, and will ultimately leave a little nubbin when finished. If you cut off the collar and make a flush cut flat to the surface of the tree, you have failed this class. Put down your saw and go stand in the corner. The trunk of the tree does not have the same ability to close a wound as the collar, and now you have made a larger wound that takes longer to close, which leaves the tree more susceptible to disease and rot.

So you make a poor pruning cut and what does it even matter? Besides the fact that the tree will not be able to close that wound properly, the tree will look aesthetically ridiculous and I’ll take pictures of it and post it on the internet. I’ve heard an arborist spills their coffee somewhere in the world every time a bad cut is made, but that might just be old lore. If. You don’t know where to make a cut, just cut out the limb a little further and the tree will use that little stub to hold a bird’s nest or it could be a foothold for a kid to climb the tree maybe. Don’t rush the process, take your time and make 2-3 ‘finishing cuts’ if you have to, but don’t overlook that trees are alive and need a good ‘doctor’ with precision cuts!