Pruning shears in hand and you’re ready to start chopping. Well, not so fast. While you may be going at it with good intentions, it is possible that incorrect pruning could kill your tree.
Mature trees, unlike shrubs and bushes, have a much larger and more complicated vascular system that delivers water and nutrients to keep the tree alive. Wound-healing systems are slower and more deliberate.
Read through this short DIY pruning guide to understand how you can help your tree through pruning, not hurt it.
Opt for a pruning saw
Pruning saws, unlike handsaws or lopers, stay super sharp, fit more easily into tighter spaces, and cut more precisely. Pruning saws cut slowly and evenly without tearing the bark, making the healing process easier on your tree. Most decent pruning saws cost between $15-$40 but can last a lifetime.
Prune at peak visibility
There is no “best” time of year to prune a tree. A tree needs to be pruned when it needs to be pruned. Pruning in the late fall or early winter, however, is easier because the canopy is bare and you are able to see branches more clearly.
Don’t cut the top
Unlike shrubs that can be shaped from every angle, tree shaping isn’t really a thing. Pruning shouldn’t be done for aesthetic reasons, only for the health of the tree or safety of property or people. You can’t give it a haircut, you’ll just have to let it be.
Diagnose before you cut
Before you start cutting branches randomly, look at the tree as a whole. Is it leaning to one side? Are branches intersecting and rubbing one another. Are branches growing downward? Are branches dead or dying? All of these are reasons to prune a branch.
Though it’s not sentient, a tree has to heal each cut you make. If it helps you not to get carried away (pruning can be fun!), think about each cut as an open wound.
Use a three-cut method
Yes, there is a correct way to cut a branch. Like a cut on your hand, the tree needs to heal the wound as quickly as possible to prevent excess moisture, fungus, and insects from invading.
Here are some definitions you’ll need to know:
- Branch collar: the swelled bottom of the branch where it meets the tree
- Branch-bark ridge: the bunched up bark on the top and sides where the branch and the tree meet
First Cut: Undercut
The first two cuts you make to a branch should remove the majority of the weight of the branch. This will be six inches to a foot away from the trunk or consecutive branch. Here, make the first cut on the underside of the branch about halfway through. This will stop excess bark from tearing off with the second cut.
Second Cut: Stub Cut
Move your pruning saw an inch or so towards the end of the branch (away from the trunk) and cut slowly and evenly all the way through from the top side of the branch. This will leave what is called a stub.
Third Cut: Final Cut
It is important to never cut through the branch collar (see above). This is where all the nutrients for new growth will come from. Cut as close to the branch collar as you can without damaging it.
From the top, just outside of the branch-bark ridge, cut even and slowly at a slight angle as to minimize the wound size and avoid the branch collar. Support the weight of the stub as to avoid tearing off the bark when it detaches.
The Bottom Line
Pruning your trees is very easy to do and equally as easy to do incorrectly. With the right tools, deliberate decisions, and a three-cut method, you can avoid killing your tree while pruning.