The Right Way to Prune a Tree

There are many good reasons to prune trees. For example, branches that were damaged from winter storms need to be removed or low-hanging branches that interfere with your ability to mow your lawn need to be cut away.

Early summer is a great time to prune trees and shrubs. But like any activity that I do at intervals that are spaced far apart, I find that it’s good to review the essentials before I begin this seasonal work.

Here are three simple rules of pruning:

1. Leave the branch collar.
2. Prune large branches in three steps.
3. Use appropriate tools.

Rule 1: Leave the Branch Collar

Regardless of why you prune, never cut the branch flush to the bark, nor cut the branch leaving a stub. Instead, cut the branch just outside the ridge where the branch connects to the trunk. Known as the branch collar, the ridge has cells that will help heal the cut. Cutting too far outside the branch collar leaves wood that will rot and this rot can spread into the tree. Cutting off the branch collar has the identical effect, creating a wound that will not heal properly—and more wood rot.

Here’s what this looks like in pruning away the stump of a branch torn off from a winter storm.

The pencil points to the branch collar, the ridge of raised wood where the branch connects to the tree trunk.

Using a bow saw, cut away the stub, just ahead of the branch collar.

This is what the pruning cut should look like after you’re done. The stub has been cleanly removed and the branch collar is left intact to begin the healing process. For larger branches, see the three-step pruning method described below.

Rule 2: Remove Big Branches With Three Cuts

When removing a large branch, first make a partial cut on the bottom of the branch, uphill, and at least several inches away from the branch collar. This way, when you cut away the branch, you don’t risk having the falling branch tear away a strip of bark from the tree as it falls. If you don’t manage to cut through the branch entirely before it falls, and some bark remains, the tearing bark will be interrupted by the first partial cut you made on the bottom of the branch. The bark will tear free there and the branch will fall the rest of the way to the ground.

Make the second cut from the top of the branch down, at least a couple of inches uphill from the first cut.

After the branch falls free, cut the remaining stub of wood that’s left, leaving the branch collar intact.

Here’s what the cut sequence looks like using a pencil to point out the position of the cuts.

The pencil is pointing to the location of where you would make a partial cut on the bottom of the branch, uphill from the collar. All you need is a cut no more than an inch deep.

The pencil is pointing to where you would make the next cut, an inch or two uphill from the first cut, and from the top of the branch. The cut branch will fall free.

The pencil shows the location of the final cut and its angle that removes what’s left of the branch. The three-cut sequence removes the branch and leaves an easily removed stub. The method is a much safer means of removing limbs without damaging the tree and is particularly useful for amateurs who don’t prune trees every day.

Rule 3: Use an Appropriate Tool

Forget what manufacturers tell you about the diameter that their pruning tools will cut. I’ve tested pruning tools for decades and I’ve never seen one that will consistently cut what its manufacturer claims. There are just too many variables here to consider in terms of wood hardness, access to the cut, and the person’s strength.

All that aside, the important thing to remember here is to use an appropriate tool to prune. Use bypass pruners on small branches, loppers on medium-sized branches and a saw on big branches. For example, if you try to use loppers on a branch that you should saw through, you’ll get the tool stuck midway.

FELCO F-2 bypass pruner

Now 20% Off

$59 at Amazon

Use a simple pair of bypass pruners for cutting away most small branches, from ¼ inch to 3/8 inch diameter.

Fiskars PowerGear 2

$45 at Home Depot

Use loppers for 3/8 inch thick wood up to, maybe, ¾ inch, providing the wood is soft and moist enough to cut easily.

Fiskars 370300-4003 Bow Saw

$10 at Lowe's

Use a bow saw (electric chainsaw or pruning saw) to cut larger branches. Again, use the 3-cut method: make a bottom cut uphill from the branch collar, make a cut down from above to remove the branch, and then remove the stub, leaving the branch collar intact.

Roy Berendsohn

Senior Home Editor

Roy Berendsohn has worked for more than 25 years at Popular Mechanics, where he has written on carpentry, masonry, painting, plumbing, electrical, woodworking, blacksmithing, welding, lawn care, chainsaw use, and outdoor power equipment. When he’s not working on his own house, he volunteers with Sovereign Grace Church doing home repair for families in rural, suburban and urban locations throughout central and southern New Jersey.