高枝鋏・高枝鋸の使いどころ──地上から切れる枝の太さ、付け根での刃の当て方、電線の近くで使わない理由(Pole Pruners and Pole Saws: When to Reach from the Ground)

Pole Pruners and Pole Saws: When to Reach from the Ground

This article shows, with illustrations, when Japanese gardeners use the pole pruner and the pole saw in garden tree pruning: how thick a branch can be cut from the ground, where to place the blade at the branch base, where to stand so a falling branch misses you, and why these tools are never used near power lines. It draws on the USDA Forest Service, university extension services, Japan’s product safety standard and a gardener’s field experience.

This is the thirteenth article in our series on the pruning techniques of Japanese gardeners (niwashi, ueki-ya). Last time we covered the tripod ladder. This time we look at the long-handled tools that reach a branch from the ground, without climbing a ladder.

What the pole pruner and the pole saw are

The pole pruner (takaeda-basami) has a blade at the end of a long pole and is closed by a cord or a lever at the handle. Japan’s SG safety standard for pole pruners, set by the Consumer Product Safety Association, divides them into types whose blade is moved by a lever or handle and types moved by a pull cord, and into poles that do not extend and poles that do. The type most often seen in gardens has a telescopic pole and is cut by pulling a cord.

The pole saw (takaeda-noko) is a telescopic pole with a gently curved saw blade at its end. Like other Japanese saws, it cuts on the pull stroke. A small hook at the tip of the blade is used to seat the blade on a branch or to pull a cut branch toward you.

左が高枝鋏(かぎ形の受け刃と動く刃。ひもを引くと刃が閉じる)、右が高枝鋸(反った鋸の刃と刃先のかぎ)。どちらも柄が伸び縮みする

Iowa State University Extension recommends pruning from the ground rather than from a ladder whenever possible, and names the pole pruner and pole saw as the tools for it. With both feet on the ground, less of your strength goes into keeping your balance than on a ladder. We described the setup and the risks of the ladder in the previous article, The Japanese Tripod Ladder: Setup and Safety. Pole tools are also tools for climbing a ladder less often.

Branches you can cut from the ground, and branches you cannot

The pole pruner suits thin twigs that stick out from the outside of the crown. You hook the fixed blade over the twig and pull the cord, and the twig is cut from the ground in a single action.

樹冠の外に出た細い小枝に受け刃を掛け、ひもを引いて地上から切る

The jaw of a pole pruner only takes so thick a branch. The USDA Forest Service guide How to Prune Trees says that pole pruner heads generally cut branches up to about 4.4 cm (1.75 in) in diameter. From our field experience, though, the pole pruners common in Japanese gardens are used on twigs about as thick as a pencil, and we switch to the pole saw for anything thicker than a finger. Forcing a branch that does not fit deep into the jaw keeps the blade from closing, crushes the bark and tears it.

左は細い小枝が刃の口の奥まで入り、刃が閉じる。右は枝が太く、口に入らず刃が閉じない

Medium branches are cut with the pole saw. A pruner’s jaw may reach a lower limb or the base of a branch inside the crown, but it will not fit around it. With a pole saw you set the blade at the branch base and cut by moving the pole back and forth.

下枝の付け根に高枝鋸の刃を当て、地上から切る。立つのは枝の真下ではなく横

Here is a summary of the guidelines in the sources.

Sources: USDA Forest Service, How to Prune Trees; Iowa State University Extension, Guide to Pruning Equipment; National Institute for Land and Infrastructure Management (Japan), guide to street tree regeneration

Thicker or higher branches are not work for tools used from the ground. A guide from Japan’s National Institute for Land and Infrastructure Management organizes the equipment to prepare by working height (tripod, ladder, aerial lift, rope work) and the tools by branch size (shears, pruning saw, chainsaw).

Set the blade just outside the swelling at the branch base

On a long pole, the tip of the blade is hard to see. With a pole saw it is easy to cut partway along a branch and leave a stub. Colorado State University Extension also notes that it can be hard to make good cuts with a pole pruner.

左は枝の途中で切り、長い切り残しが出る。右は付け根のふくらみのすぐ外で切る

The cutting position is the same when you cut from the ground. Keep the raised bark on the upper side of the branch base and the swelling on its lower side, and cut just outside them. How to find the branch base is covered in our article Where to Cut: The Branch Collar in Japanese Pruning Practice.

A heavy branch tears the bark below its base under its own weight. The USDA Forest Service guide shows the order: first a shallow cut on the underside, then removal of the branch further out, and finally a cut of the short remaining stub at the base. With a pole saw held from the ground, there is a limit to how thick a branch you can take through that sequence cleanly. Branches that are hard to undercut from below, or too heavy to control, are cut from a ladder or aerial lift, close to the branch. The sequence is described in detail in our article The Three-Cut Method for Large Limbs with a Japanese Pruning Saw.

Where to stand and how to hold: never under the branch

Japan’s SG standard requires the instruction manual of a pole pruner to say that it must not be used directly below falling objects, and that safety glasses and a hat must be worn. A cut branch drops the moment the blade comes through. A guide from Japan’s National Institute for Land and Infrastructure Management warns that a cut branch can fall like an arrow.

左は切る枝の真下に立ち、落ちる枝が頭の上へ来る。右は枝の横に離れて立ち、枝は離れた所へ落ちる

Stand to the side of the branch base, on the side opposite to where the branch end will fall. From our field experience, a cut branch can catch in the foliage and stay there, then drop without warning later. When you finish a cut, look up to check that nothing is left hanging before you move to the next branch.

Keep the pole as upright as you can and hold it close to your body. If you lay the pole down and thrust it at a distant branch, the blade tip wobbles and the weight falls on your arms and lower back. From our field experience, taking one step toward the tree, raising the pole and keeping both hands close to the body steadies the blade tip.

左は柄を立て、両手を体の近くで握る。右は柄を寝かせて遠くへ突き出し、腕が伸びきって上半身が傾く

Before use, check the locks on the telescopic pole. In 2020 the U.S. Consumer Product Safety Commission announced a recall of pole saw pruners because the telescoping pole could separate and the saw blade and pruner head could fall. If you extend the pole with a loose lock, it can slide shut or come apart while you work.

柄を伸ばしたら、つなぎ目の締め具を固く締めてから使う

Never near power lines

Japan’s SG standard requires the instruction manual of a pole pruner to say that it must not be used near power lines, to prevent electric shock. The USDA Forest Service guide also says that pole pruners should not be used near power lines except by qualified line-clearance workers. Clemson University Extension warns that aluminum poles conduct electricity and should not be used near power lines.

枝先が電線に触れかけているときは、高枝鋸を伸ばさず、電線から離して確かめる

A publication of the U.S. Occupational Safety and Health Administration (OSHA) requires staying at least 10 feet (about 3 m) from overhead power lines and preventing indirect contact through branches and tools, and describes a case in which a worker was killed when a pole saw used from a work platform touched a line. In Japanese home gardens too, power lines often run right beside the trees. When branch tips are close to or touching a line, we do not raise the tool from the ground; we consult the power company or whoever manages the line.

The craftsman’s eye: letting the feel of the hand reach the end of the pole

Among Japanese craftsmen it is said that pole tools, too, are an extension of the hand. When you cut a branch with hand shears, the feel of the blade on the branch tells you how hard the wood is and how the blade is going in. From our field experience, even at the end of a long pole, the hands on the grip feel the blade catch on the branch and the saw teeth bite into the wood. That feel tells you whether the blade has slipped off the branch base, and whether the branch is starting to tear.

Among Japanese craftsmen it is also said that, before cutting, you must read the branch bases from beneath the tree. From the ground, overlapping branches hide the bases. You walk around the tree, follow with your eyes where each branch comes from, and only then decide which branch to set the blade on.

Japanese garden care values a finish in which the cuts do not show. Work such as the final stage of sukashi (thinning), choosing and keeping fine twigs one by one, can be done more finely the closer your hands are to the branch. From our field experience, we use pole tools to clear the branches we can reach from the ground first, as part of preparing the work, and do the finishing close to the branch with hand shears. When the cutting is done, we look up at the cuts from the ground to check that no stubs are left.

切る前に、高枝鋸を立てたまま樹冠を見上げ、枝の付け根を目で追う

Pole tools are convenient because they reach distant branches. But reaching a branch and cutting it in the right place are not the same thing. We cut with pole tools only the branches whose base we can set the blade on from the ground; beyond that, we get close to the branch from a ladder or aerial lift, or leave it to the work of climbing the tree. Our way of thinking about work high in a tree is set out in our article on arborists, comparing traditional tree climbing with modern methods.

Frequently Asked Questions (Q&A)

Q1. How do you choose between a pole pruner and a pole saw?

A. The pole pruner cuts thin twigs on the outside of the crown by closing the blade with a cord or lever. The pole saw is set at the base of a lower limb or medium branch and cuts on the pull stroke. If a branch is too thick for the pruner’s jaw, do not force it; switch to the pole saw.

Q2. How thick a branch can a pole pruner cut?

A. The USDA Forest Service guide says pole pruner heads generally cut up to about 4.4 cm in diameter, and Iowa State University Extension gives about 5 cm for pole saws and pruners. The size of the jaw differs by product, so use the tool within the range in its instructions.

Q3. May I cut a thick branch with a pole saw?

A. A thick branch tears the bark at its base under its own weight, so it needs a shallow undercut first, then removal, and finally a cut at the base. Branches you cannot take through that sequence from the ground with a pole saw, or that are too heavy to control, are cut from a ladder or aerial lift, close to the branch.

Q4. Where should I stand when using a pole pruner?

A. Never directly under the branch you are cutting. Stand to the side of the branch base, opposite to where the branch end will fall. Japan’s SG standard requires the instruction manual to say that the tool must not be used directly below falling objects and that safety glasses and a hat must be worn.

Q5. May I cut a branch near a power line with a pole pruner?

A. No. Japan’s SG standard requires the instruction manual to say that the tool must not be used near power lines, to prevent electric shock. OSHA in the United States requires staying at least 10 feet (about 3 m) from overhead lines. When a branch is close to a line, consult the power company.

Sources

– Consumer Product Safety Association (Japan). SG Standard for Pole Pruners, CPSA 0104.
– National Institute for Land and Infrastructure Management (Japan). Guide to conservation measures for landscape-important trees (2010).
– National Institute for Land and Infrastructure Management (Japan). Guide to street tree regeneration.
– Bedker, P. J., et al. How to Prune Trees. USDA Forest Service, NA-FR-01-95 (revised 2012).
– Iowa State University Extension. Guide to Pruning Equipment.
– Clemson University Home & Garden Information Center. Pruning Trees, HGIC 1003.
– Colorado State University Extension. Pruning Cuts.
– OSHA. Electricity and Tree Care Work: A Deadly Combination, OSHA 3861 (2016).
– U.S. Consumer Product Safety Commission. Recall 21-044 (December 9, 2020).

Masatoshi Nakamura
Jumokui (Tree Doctor), Toshi Landscape Co., Ltd., Tokyo