How to Prune a Tree Branch

As an Amazon Associate we earn from qualifying purchases.

How to prune a tree branch correctly depends on the branch’s size and on the cut you make first. Four extension pages, from Iowa State, Clemson, Purdue and a Kenosha County brochure, agree on the core method: a three-cut sequence that keeps the bark from tearing and finishes just outside the branch collar. They differ on the distances, and this guide shows where.

Read on for the size rule, the three cuts in order, the spacing each page gives, and the points the pages leave open.

Quick answer

Use the three-cut method for a limb that is larger than about 1½ inches across, the line that Iowa State and Clemson both use.
Make the first cut as an undercut from below, about one-third of the way through the limb, a set distance from the trunk. The distances differ by source.
Make the top cut past the undercut, so the limb falls before its weight can tear the bark.
Finish the final cut just outside the branch collar, and skip paint, which the Kenosha County brochure calls unnecessary.

Start with the purpose and the tree’s shape

The Kenosha County brochure opens with a question: “Have a purpose before making any cut.” Its two purposes are different. Young trees are pruned “to establish good branch structure and spacing, a central trunk and proper trunk taper.” Mature trees are pruned “to remove dead and/or hazardous limbs.” The same brochure says “Young trees can tolerate more branch removal than mature trees,” and that the amount depends on the tree’s size, species and age as well as your pruning objectives.

Purdue adds the shape of the tree to the decision. “The shape of a tree is determined by genetics.” Trees with a central stem form a pyramid shape that Purdue calls excurrent growth, and round-shaped trees have a decurrent pattern. “The pruner should consider these natural shapes before beginning the job,” and “A properly pruned tree should maintain its natural shape.”

Timing depends on the tree

The pages do not set one season for all trees, but they give useful timing points. The Kenosha County brochure warns: “The worst time to do major pruning is in the spring, when tree buds and/or leaves are still growing and food reserves are low.” It also says “Dead limbs may be removed any time of year.”

Clemson gives a different rule for flowering plants. They “develop blooms on old wood,” so pruning them in winter “removes these flower buds,” and the page says to “wait to prune until AFTER all flowers have faded.” For shade trees and large shrubs that are not grown for a flower display, its general line is: “Shade trees and large shrubs that are not grown for a flower display can be pruned in late February.”

Know when the three-cut method applies

Three triggers appear across the pages. Iowa State uses the three-cut procedure for branches “greater than 1½ inches in diameter.” Clemson uses the same size line and adds a second trigger: “If limbs are larger than 1-1/2 inches in diameter or heavily weighted, use the three-step method for removal.” The Kenosha County brochure describes the trigger by reach. Its sequence is for “a limb you cannot support with one hand while cutting with the other.”

Taken together, a branch that is thicker than about an inch and a half, or heavy enough that you cannot hold it with one hand, is the one to cut in three steps. Our arithmetic, which is an example and not a source figure: a limb 2 inches across is above the 1½-inch line, and a limb 1 inch across is below it. None of the pages explains how to measure a limb that is not round.

Find the branch collar before you cut

Locate the collar first, because the final cut depends on it. Purdue defines it: “Branch collar is the area just below the junction where two branches meet.” Clemson describes its look as “a rough, swollen area surrounding the base of the limb.” Purdue also names the raised area next to it: “Branch bark ridge is the raised area located in the junction where two branches meet.” The collar and the ridge are the two landmarks for the last cut.

Purdue explains why the collar matters. CODIT, which it spells out as “Compartmentalization of Decay in Trees,” is the tree’s own process of “walling off or compartmentalizing wounds.” The Kenosha County brochure warns that cutting “several inches or feet from the parent limb or trunk” does not allow for “complete wound closure.”

Make the undercut first, from below

All four pages describe the first cut as an undercut made from below, about one-third of the way through the limb. They differ on how far from the trunk it goes. Iowa State says: “Make the first cut 6 to 12 inches from the main branch or trunk.” Clemson puts it “about 6 inches away from the trunk.” Purdue gives “About 1 foot from the point where two branches meet.” The Kenosha County brochure starts at 12 to 18 inches from the final cut.

The purpose is the same in every source. Iowa State explains that the undercut “prevents the branch from ripping off a piece of bark as it breaks.” Purdue says the cut “prevents the bark from tearing when the second cut is made.” Our arithmetic, converting the four starting distances to feet: from about half a foot to one and a half feet, with Purdue at one foot.

The undercut also has a floor. No page gives a distance shorter than about six inches from the trunk, so an undercut placed closer than that falls outside every source.

Make the top cut and let the limb drop

The second cut is made from above, past the undercut, and it removes most of the weight. Iowa State says: “Make the second cut 1 to 2 inches beyond the first. Saw downward from the top of the branch.” Clemson gives “3 to 6 inches beyond the first cut,” and Purdue gives “About 2-3 inches beyond the first cut, remove the branch.”

The Kenosha County brochure does not give a distance for this cut. It describes the step as “Outside the first cut, sawing from the top down, completely remove the branch,” and then adds: “With the majority of the branch weight now gone, bark tearing should not occur.” The top-cut gap is still open, because the pages give 1 to 2 inches, 2 to 3 inches, or 3 to 6 inches. They agree on the sequence, not the gap.

Finish the final cut at the collar

All four pages end at the same place. Iowa State says to “Make the final cut just beyond the branch collar and branch bark ridge.” Clemson says the final cut is “just outside the branch collar.” Purdue tells you to remove the leftover piece by “cutting just outside the branch collar.” The Kenosha County brochure describes the last step as “Begin the final cut outside the branch bark ridge, continuing at a slightly outward angle, finishing just outside the branch collar.”

Purdue calls the leftover piece a stub, and its instruction is to remove it, which is the same as cutting outside the collar. Keep the saw outside the collar and the ridge, and the stub does not form.

Protect your hands and eyes, and leave the wound open

The Kenosha County brochure says: “Pruning equipment should be sharp and well maintained.” It asks for “Loppers and hand pruners” of “the bypass or scissors type to prevent crushed limbs.” Its tool list covers a pole saw and lopper head, hand saws, a helmet with safety glasses, a hand pruner, leather gloves and a long-handled lopper. For a saw, it recommends “Saws should have triple edged teeth for quicker and cleaner cuts.” For pruning tools, see our guide to pruners for trees.

The gear list is short: “A hard hat, leather gloves and eye protection are recommended.” The brochure is the only one of the four pages that gives this kind of safety detail, so the other pages do not repeat it.

On the wound itself, the brochure is clear: “Remember it is not necessary or appropriate to paint pruning wounds.” Its goal for the finished tree is modest: “A properly pruned tree should look like nothing drastic has been done.” The brochure adds a fair test: “Good pruning should not be determined by how many branches are on the ground, but rather by what remains in the tree.”

Blades need care too. For sharpening, see our pruner sharpener guide. The sources do not give a sharpening interval, so that is a question for the tool maker’s directions.

Mistakes to avoid

Cutting the whole limb in one pass, which the Iowa State and Purdue pages both warn can tear bark.
Placing the undercut closer to the trunk than about six inches, the shortest distance any page gives.
Leaving a stub, which Purdue says to remove by cutting outside the collar.
Painting the wound, which the Kenosha County brochure says is not necessary or appropriate.
Working without the protection the brochure recommends.

How we chose

We limited the review to university and county extension pages that describe pruning a large limb by hand or with a handsaw. We opened four pages with curl on 2026-10-22 and read the extracted text. A rule went into this guide only when a page stated it in plain words, and each quoted sentence was checked against the page text before it was used. Commercial gardening sites and video pages were left out, because they could not be checked against a written primary source. Distances come from the sources. Where we converted or added up figures, the guide says so.

What we could not verify

The four pages do not agree on the distances, and none of them is a complete guide to pruning every tree. They were written for general audiences, so specific species, pruning seasons and tree sizes are outside their scope.

What the sources do not say

The pages do not agree on how far from the trunk to start the undercut, or how far beyond it to place the top cut. None of the four pages mentions a ladder or a power line, so this guide has no source for working off the ground. The pages do not set one pruning season for every tree. Clemson gives a late-February date that applies to some flowering plants, and it does not extend that date to other trees. None of the pages explains how to measure the diameter of a limb that is not round.

Frequently asked questions

Is the three-cut method always needed?

No. Iowa State and Clemson use a size line of 1½ inches, and the Kenosha County brochure uses a limb that cannot be held with one hand while cutting. Smaller, lighter limbs may not need the sequence, but the pages do not give a rule for them, so judge by weight and by how the bark behaves as you work.

Why not cut the branch in one pass?

Because the bark can tear. Iowa State explains that the undercut “prevents the branch from ripping off a piece of bark as it breaks.” Purdue says the first cut “prevents the bark from tearing when the second cut is made.” A tear on the trunk leaves a larger wound than the cut itself.

Should the cut be painted afterward?

The Kenosha County brochure says that painting is not necessary or appropriate. Leave the wound open, and make sure the final cut sits just outside the collar, as the same brochure directs.

Where should the final cut go?

Just outside the branch collar, and beyond the branch bark ridge, according to Iowa State and the Kenosha County brochure. Clemson and Purdue use the same collar landmark. The collar is the swollen area at the base of the limb, and the ridge is the raised area at the junction.

What protective gear is recommended for pruning?

The Kenosha County brochure recommends a hard hat, leather gloves and eye protection, and it recommends a saw with triple edged teeth for cleaner cuts. The brochure does not cover ladders or work near overhead lines, so check those points separately before you climb.

Sources

https://yardandgarden.extension.iastate.edu/faq/what-proper-way-prune-large-tree-branch (opened 2026-10-22)
https://hgic.clemson.edu/is-it-time-to-prune-my-trees-and-shrubs/ (opened 2026-10-22)
https://www.extension.purdue.edu/extmedia/FNR/FNR-FAQ-19-W.pdf (opened 2026-10-22)
https://kenosha.extension.wisc.edu/files/2020/09/Proper-Tree-Pruning-brochure.pdf (opened 2026-10-22)