Whenever you are using a pruning or pole saw to remove a large or long branch, you must be aware of the danger caused by the weight of a branch. Failing to properly account for this weight before you make your intended cut will almost always tear living tissue, causing unwanted damage to your plant.
This guide will teach you how to cut heavy branches in a way that is safe to your plant, making clean cuts that do not tear or snap before you are ready.
This article will not contain full instructions to keep you safe when cutting thick overhead limbs, about four inches or more in diameter. Removing high wood from trees takes skill and equipment of a professional caliber. A bad cut causes wood to swing and fall unpredictably—when large wood falls, it can kill.
But handling branch weight is still a concern for the shrub or tree’s health even when dealing with branches that are thinner or lower to the ground, which any home gardener and arborist can learn to handle.
What Is A “Heavy” Branch?
Any limb you need a saw to cut must be fairly thick, or else you would be using hand pruners or loppers. Wood this thick is structural, like the beams in a house: they bear weight importantly, and removing them is a process like the careful demolition of a house.
A rule of thumb I’ll suggest for when a branch is “heavy” is this:
A heavy branch is any branch that, after you cut it completely from the plant, you would not be able hold still with one hand.
This rule can apply because the wood is
- too high to reach.
- so long that the torque of its weight would turn your hand.
- too heavy to hold.
Over time, you’ll learn what wood is too heavy to hold in place with your non-cutting hand. When in doubt, use the techniques in this article to remove the weight from the limb with preliminary cuts before your final cut.
The Wrong Way To Cut A Heavy Branch
The wrong way to cut a heavy branch is to saw through it at the point where you want to cut it off. Here’s what will happen when you do that, sawing from top to bottom: things go fine as you begin. As you cut away the wood, however, you may notice the branch starting to bend downward as it loses its support. Eventually, you have just a small hinge of wood left which very suddenly bends, snaps, and in breaking violently tears a strip of wood from the plant. You’ve just wounded your plant.
The Right Way: Removing Weight With Preliminary Cuts
The key to cutting a large limb is that a single pruning becomes a two-phase process. In the first phase, you aren’t trying to make a perfect pruning cut at the right place on the plant, just above a node , etc. In this first phase, you are just removing weight.
Remove branch weight with a cut or many cuts that are a good foot or more from where you have planned to make your final pruning cut. This foot of buffer distance means that even when wood makes a hinge and peels, it will only wound wood that you will cut off later. Your plant remains unharmed.
At the end of your preliminary cuts, the piece of the branch that you leave stuck to the plant should be much smaller and lighter.
As a guideline, it should be a piece that you could lift easily with one hand.
Making A Jump Cut: An Efficient Way To Keep Your Plant Safe
Once you’ve taken off nearly all of the branch weight with preliminary cuts, you can often just use your saw to make your final cut where you want it. Really, though, to be perfectly safe, you should precede your last cut with a jump cut.
A jump cut is a cut that prevents the formation of that dangerous wood hinge—the one that you make as you saw through wood and leave a smaller and smaller part behind. Instead of the branch swinging, the jump cut makes it “jump” away from the plant.
To make a jump cut, choose a spot on your branch a few inches away from where you will make your final cut. There, cut from the opposite side you normally would. Usually, this means you are sawing upwards through the underside.
This can be uncomfortable, but you won’t have to do it long.
Cut into it just a few heavy strokes—well less than halfway, perhaps just a quarter way through. This cut shouldn’t cause the branch to move at all.
Now, remove your saw and make your final cut, usually from the top down. When the branch falls away, it will break along the cut in progress and your jump-cut. When done right, the branch falls perfectly vertically, no bending or swinging, and no tearing wound to your plant.
You can see Sean Dembrosky demonstrate the jump-cut technique about 2/3 of the way through the end of his video on simple pruning practices. The branch he cuts is smaller than many you would need to use a jump cut on, but the three-cut technique he demonstrates is correct and the same you'd use for larger branches.