Pinching Japanese Maple Bonsai Spring Buds: Why and How

Pinching spring buds on a Japanese maple bonsai involves removing the stipules and bud scales, as well as the center leaf. This technique maintains the bonsai’s size and promotes fine branching. It’s best done before the leaves open in spring.

Pinching Japanese maple bonsai spring buds

Pinching spring buds

Bonsai pinching is an important technique used to maintain the size and encourage the ramifications of a bonsai tree.  It involves removing the tips of new growth on a tree’s branches, which suppresses the apical dominance and promotes lateral buds to open up.

In other words, removing the tips of new growth produces multiple buds in the area where the cut was made.  These new buds will sprout into new leaves and branches, and eventually, the tree will develop a fuller canopy.

When done correctly, pinching stimulates the production of new growth on the tree.

Structure of Japanese maple spring buds

A young Japanese maple leaf is composed of several parts including the leaf (leaf blade), stipules and bud scales.

Leaf

At the very young stage, the leaf of Japanese maple is pointy and somewhat cylindrical.  There are usually three baby leaves in a bud but it depends on the species.

Stipules

Stipules are small, leaf-like structures that cover the base of the leaf stalk, which is attached to the branch.  They protect the young, emerging leaf from cold and ultraviolet rays.  There are usually two stipules on Japanese maples, though they might be more or absent depending on the species.

Bud scales

Bud scales are small, scale-like modified leaves that protect the bud and emerging leaf, which are located at the base of the leaf stalk.  During winter, they enclose and protect the embryonic cells of leaves which remain dormant for extended periods.

These scales can be either green or red/brown.  There are usually three pairs of bud scales totaling six bud scales in Japanese maples but only two pairs (four bud scales) are easily observed.

As the Japanese maple leaf opens and matures, the leaf scales and stipules are shed, leaving only the leaf blade.

What to and why pinch Japanese maple spring buds

Pinching spring buds of Japanese maple bonsai breaks into 2 parts: (1) removing stipules and bud scales, and (2) removing the center leaf.

Promote shorter internodes

Pinching stipules and bud scales help to shorten internodes.  Removing them exposes young leaves to the outside air that are otherwise protected at a young stage.  The leaves would dry out, suppressing the growth of the first internode.

This technique is especially effective on the tips of branches where we want a lot of shorter internodes with fine branches.

Increase Ramification

Removing the center leaf of the early-emerging buds can direct more growth energy to weaker buds.  It can also help fine branches maintain a compact shape with shorter internodes, and protect the lateral buds that might be stunted by environmental stresses.

When to pinch

Timing is crucial when it comes to pinching your Japanese maple bonsai tree.  Pinching spring buds too late may not be as effective as doing it at the right time.

The best time to start pinching your Japanese maple bonsai is in the early spring when new growth begins to emerge and leaves have just come out of buds.  At this time, the tree is starting to wake up from its winter dormancy and is ready to begin growing again.

The ideal moment is before the leaves open up which look pointy and somewhat cylindrical.  If leaves are already opened, it is a bit late.

It is important to note that new Japanese maple buds should be pinched as they emerge.  Leaves continue to emerge from buds for about a month after they started to grow.  Keep watching your tree carefully and pinch off before the leaves are fully open.

Pinching Japanese Maple Bonsai: Step-by-Step Guide

Essential Tools for Pinching a Japanese Maple Bonsai

To effectively pinch the spring buds of your Japanese maple bonsai, you will need tweezers.

They can be used to carefully pluck off small buds and leaves that are too small for pruning shears.  There are tweezers with bent tips which are also useful for pinching.

If leaves become large enough, you can also use leaf scissors, which are specialized scissors designed for trimming the leaves of bonsai trees. They are smaller and more precise than regular pruning shears, making them ideal for trimming the delicate leaves of a bonsai tree.

A step-by-step guide to pinching spring buds

Pinching is a simple technique that is used to maintain the beauty of your Japanese maple bonsai tree.  Here’s a step-by-step guide on how to pinch spring buds of your Japanese Maple bonsai.

Step 1: Remove stipules and bud scales

Using tweezers, remove stipules and bud scales.

Be extra careful when peeling them because new buds are soft and delicate.  It is fairly easy to take stipules off but you may find it difficult to remove bud scales.  If you think you have to force somehow to do that, just leave them.  Damaging the base of the buds can hurt the growth of new leaves.

Also, be careful not to touch lateral buds just below the new bud.  They are the next buds to grow into leaves and branches.

Step 2: Remove the center leaf

Using tweezers (or leaf scissors), remove the center leaf.  It is still very soft so you don’t need to pinch hard.

If you think removing stipules and bud scale buds takes too much time, you can only take off the center leaf, which is still effective.

Step 3: Repeat as Necessary

Pinching spring buds should be done each time new buds emerge.  You may need to pinch regularly for about a month or so in spring.  Be sure to monitor your tree and pinch as necessary.