What is bonsai pinching ?
Bonsai pinching is a basic technique of bonsai styling. It can be used on many bonsai trees species and, when used correctly, leads to a finer ramnification of the crown of the bonsai. Pinching is mostly used for well-developed bonsai, less often for prebonsai. In the case of prebonsai, the basic structure of the bonsai tree is still being worked on. Therefore, it is usually too early for the technique of bonsai pinching.
Essentially, bonsai pinching means removing with your fingers the end bud or the tip of the shoot.
The shoot tip of trees produces growth hormones. These growth hormones inhibit the budding of the underlying buds. If the end bud is removed, the other buds can sprout because the inhibition by the plant hormones disappears.
There is a better ramnification. The bonsai tree does not grow tall. The crown becomes denser and more compact. In addition, more flower buds are created on many trees. An often desired effect.
What are the advantages of pinching bonsai ?
- The "sleeping" buds of a bonsai tree are activated. The degree of branching of the crown of the bonsai increases significantly
- Unpinched, weaker shoots are strengthened by "slowing down" the grow of stronger shoots. The risk is reduced that the weaker shoots die off (e.g. White pine bonsai)
- The distances between the knots on a new shoot remain smaller by pinching the bonsai. The crown becomes more compact and fine (e.g. Maple bonsai)
- If pinching increases the ramnification of the crown of the bonsai, the leaves usually become smaller
How does bonsai pinching work ?
When pinching a bonsai the top bud (sometimes even more) on the new shoot, which should not grow in length, must be removed.
In the very early stages, young shoots break easily on a bonsai tree. That is why you do not need a bonsai scissor to remove the end bud of most tree species. The top bud can be easily broken out with your fingers.
The time when a bonsai has to be pinched depends heavily on the bonsai tree species and the stage of development. It is definitely a bonsai refinement technique that is only used during the growing season. In most cases from April to August.
Pinching an ash maple bonsai
The ash maple (Acer negundo) grows very quickly as a bonsai tree. This means that a handsome prebonsai can be built up quickly.
But when it comes to building a fine crown, this strength of growth disturbs. Often there are less than 2 weeks between the budding of a bud and a shoot with a length of 15-20cm. Then the leaves are already very large and the knots on the new shoot are too far apart.
This is annoying even with large bonsai. In addition, stronger shoots take the lead, grow faster than the rest and the weaker shoots may die.
If this strong growth is slowed down at an early stage, especially at the top of the bonsai, the ramnification of the bonsai tree will be much better. To do this, the bud at the top is removed. The suitable technique for this is pinching. After that, several buds often sprout further inside. And the more and finer branches the ash maple has, the smaller the leaves are.
How does it work ?
Very simple: The top bud of the new shoot must be removed as early as possible.
Young shoots of an ash maple break easily in the very early stage of the shoot. No scissors are needed to remove the end bud. The shoot tips can be easily broken out with your fingers (Picture 1).
If you miss the time, you can cut the new shoot 2-3cm behind a knot (Picture 2). Don't cut too short behind the knot. The fast-growing ash maple lets the rest of the tip die. You can break it out or cut it later.
Only pinch the new shoots on the strongly growing branches (mostly in the tip area of the crown). Unpinched, weaker branches in the lower area are strengthened.
When are Acer negundo bonsai pinched ?
You can pinch the Ash maple throughout the entire growing period from April to August. And in many cases you have to do this. Otherwise it grows out of shape quickly.
Picture 3: Green arrow: 4-5 days late to break out. Breaking out is still possible, but it is no longer that easy. Yellow: The perfect time to break out is in 2-3 days. Red: too late to pinch. Now you have to cut.