Concave Branch Cutter – A Perfect Bonsai Tool

The concave branch cutter, also known as Mataeda Hasami, is one of the most difficult bonsai tools to substitute when creating bonsai. This tool enables bonsai owners to prune their plant’s branches without damaging the main stem. If you don’t want to scar your bonsai when pruning it, use a concave branch cutter.

Courtesy of American Bonsai

Personal Insight

When I began creating bonsai, “real” bonsai tools were not that accessible. I would cut a branch off with heavy garden shears and then scrape the nub with an Exacto knife. 

My first real concave cutter seemed like a miracle.  It did exactly what its name says. It took less time and did a much better job. The unsightly stubs along branches and trunk lines were quickly eliminated, no “shaving” needed.  This tool comes in at least four sizes, and several variations.

Courtesy of American Bonsai

Buying Tips

Do not buy the two very smallest unless you intend to work with very small plants.  The largest size cutter takes most people two hands to manipulate.

The medium size (approximately 8″) is good for most pruning unless you are working with very large branches. In that case, you may even consider a saw first. Do not purchase what is called a “melon cutter” until you have more experience.

Using the Concave Cutters

If the wood of a branch is especially hard, take a few “bites” at a time. Even though they are overall very sturdy, bonsai tools can break. Never force any tool!

Be sure you have the correct size to do the job. Forcing it can cause damage to the equipment, your tree, and sometimes yourself.

When NOT to Use A Branch Cutter

Some plant examples with these segments (but not the only ones) are:

The reason not to use the concave cutter, in this case, is that these segments will die back to the next ring when cut into. Keep in mind, that any trees that tend to have ‘die-back’ should be flat cut, not concave.

Pitchecellobium tortum, also known as Chloroleucon tortum (the Brazilian raintree) is another good example of when not to use this bonsai tool.

Working on a tree with obviously segmented branches? You will see the rings on stems, branches or trunk. Put away the concave cutters.  They often cut into a different segment than you intended.

Select Tools Carefully

There are several types of branch cutters. One that looks similar is the spherical knob cutter. This tool makes a much deeper cut and is not recommended as a first tool.

If you are only going to buy one “real” bonsai tool, a concave branch cutter is the one.

Where to Go From Here

The concave branch cutter is just one of the ‘first’ tools‘. There are many other bonsai tools to consider.

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