Bonsai Concave Cutter: What They Are and How to Use Them

  • By: Josh Koop
  • Date: February 8, 2023
  • Time to read: 5 min.
Affiliate Disclaimer

As an Amazon affiliate, we earn from qualifying purchases. I prefer to be honest and upfront with my readers that this doesn't change my beliefs in products nor services!

To know what Bonsai concave cutters are, it is necessary that you first know what Bonsai is. Unlike other trees that grow on the ground, Bonsai are little trees that grow in small pots. They usually have stunted growth due to being kept in the pots. They possess Japanese roots, which are the traits they are well known for.

To properly care for your Bonsai trees, it is necessary to know the essential tools. If you have Bonsai around your house, the bonsai concave cutters are one of the essential pieces of bonsai equipment you could ever use. You can use the Bonsai concave cutters to trim off either living or dead branches from your Bonsai.

It is difficult to replace Bonsai concave cutters with other tools. This is because of the way its cutting edges are structured. The concave cutters are structured such that they possess open-shaped jaws, which leave behind stretched wounds on the cutting but the wounds heal very fast with very few scars.

This article provides a lot of information on Bonsai concave cutters and emphasizes how you should use them. If you want to buy a Bonsai concave cutter and have no idea how it works, this article is a must-read for you!

What are Bonsai concave cutters?

As stated above, Bonsai concave cutters are essential bonsai tools that one can that are used to cut off branches from both living and dead trees ( bonsai) and leave the tree with a perfectly clean cut.

Bonsai cutters are products of either stainless steel or carbon steel. It is more affordable to use carbon, but it is highly liable to corrosion, demanding that you often keep replacing your tools. However, stainless is a preferable option though it is very expensive.

The bonsai concave cutters have concave-shaped jaws which leave behind stretched wounds on the cutting. The wounds heal very fast with very few scars resulting in a clean cut. This is one of the greatest advantages associated with the bonsai concave cutters. It would be best to be very careful when handling your Bonsai concave cutter because they are very sharp. You can also use them to remove the bark of your trees.

Types of Bonsai concave cutters.

There exist several types of Bonsai concave cutters available for you to use. They include:

  • Black bonsai cutters:

This is the type that is frequently purchased by many. They are usually coated black before polishing. However, the quality of the bonsai cutters does not depend on the black coating applied to them.

  • Stainless steel concave cutters:

This type looks stylish compared to the black concave cutter. Nevertheless, it does not qualify to be better than the black concave cutters.

  • Round concave cutter: 

You can describe it to look like a straight cutting edge normal Bonsai concave as well as a round-headed or knob cutter. It gives a more rounded cut when used to prune Bonsai. Their cuts are deeper and can resist greater forces, making them difficult to be curved open.

How to use a Bonsai concave cutter 

There are many things to consider when using a bonsai concave cutter. It is, therefore, precautious that you know these things as well as implement them. They include:

  • It is important to know which bonsai concave cutter size fits your tree size. For very small-sized bonsai trees, the recommendation is to use the small-sized bonsai concave cutters below 20cm. if you are a big fan of Bonsai, you’ll probably need the concave cutters in the range of 21-27cm.
  • When using the bonsai concave cutters, make sure to cut the Bonsai longitudinally to the trunk or branches and not to the side or laterally. In this way, you injure fewer sap paths making the wound grow jointly, at a faster pace, and a lot better.
  • Avoid cutting very strong branches immediately after buying your Bonsai concave cutter. More emphasis is laid on the smaller bonsai cutters whose cutting edges can be curves open when a great force is applied. You must also have a feel for your Bonsai concave cutter.
  • When you use a sharp concave cutter, it leaves the Bonsai with a perfectly clean cut. These wounds on the Bonsai grow jointly and at a faster pace. It is also possible for you to easily do a precise recut when you use Bonsai concave cutters of very high quality.
  • To prevent rust and maintain your Bonsai concave cutter, it is recommended that you use the Ballistol tool oil on it. Make sure you properly clean and grease the tools after every work session. This is the only way to ensure that your cutters run smoothly without any risk of rusting.

What sizes exist for a concave cutter for Bonsai?

  • Small size: They are Bonsai concave cutters below 20cm. If your bonsai tree is of height 30cm or below, this concave cutter is definitely for you. They provide very beautiful work for small bonsai trees.
  • Medium size: They exist in 20-22cm. You can call them the standard concave cutters for cutting Bonsai. This type is suitable for removing branches of diameter up to 1.5cm.
  • Large size: they exist in 26-36cm. They are suitable for Bonsai as high as 50 cm or above. You can also use this type to cut off branches of thickness 3cm as diameter.
  • Extra-large size: These are bonsai concave cutters greater than 70cm. It is suitable for a huge garden of Bonsai and is considered a substitute for saws.

Since the small cutters are only used for very small trees, you should only purchase them if you are to work on very small trees. The most frequently used concave bonsai cutters range between 21 and 27cm and are called medium and large in most shops.


The wounds produced by the bonsai concave cutter heal very fast, leaving little or no scar, and should not be used when you intend on leaving a scar on the branches or trunk of your bonsai tree. It would help if you did not use it on very small twigs and branches. This is because you can harm yourself or your tree compared to using a small branch cutter or sometimes scissors.


They are many other bonsai tools aside from the Bonsai concave cutters. If you have had other bonsai tools before, you should be able to tell that the Bonsai concave cutter is one of the essential tools for a bonsai tree. When you use it properly, the wounds produced heal very fast and a lot better, leaving behind little or no scars even if the branches cut off are very large.

It comes in various sizes and qualities, as mentioned in this article. Therefore, you should be careful when choosing to be sure that what you pick corresponds to your bonsai tree size.