Bud pruning is a technique used mostly along with branch pruning and is done while working on a developed bonsai. The aim of both these techniques is to develop small branches and leaves to add perfection to the final form of the bonsai. When a bonsai tree has been completed as regards its shape or when the branches are not needed to be proved but only suppressed, bud pruning or pinching is used instead of branch pruning. Bud pinching should be done when the new buds appear and in this process, only apical buds need to be removed to slow down the growth of the branches. These apical buds encourage the growth of the branch. Pinching them off slows or stops the branch growth. It also helps control the size of the tree and uniformity of
its growth. Bud pruning should be focused on the older branches near the top of the tree.
Method of Bud Pruning:
Bud pruning is done by pinching buds off either by hand or pruning with Scissors. Both these methods are equally good and it is important that the unwanted parts are removed as soon as they come out because these apical buds encourage the unwanted and uncontrolled growth of the foliage. Pinching these buds off will slow down or stop the branch's growth as a result of which the size of the tree is controlled and growth is uniform. The focus should be on pinching the buds on the older branches near the top of the tree while pinching the buds at the bottom should be controlled. The tree should be watered and well fertilized before and after the bud pruning activity.
When to Choose Bud Pruning over Branch Pruning:
Bud pruning is preferable to branch pruning in a couple of situations. If the Bonsai already has a completed form, then limb pruning can compromise that form. Pruning the buds instead allows you to maintain the form without extra growth. Pruning the buds is also preferable if your goal is to suppress branch growth without pruning it. This might be with a limb that you have chosen to keep deliberately overlong or one that has simply reached its completed length and no longer needs to continue growing.
These are several other reasons for choosing to prune buds: If your deciduous tree already has attracted branches and lush foliage, you will want to pressure that- bud pruning is preferable to retain the tree's beauty. With coniferous trees, bud pruning is done instead of leaf pruning because leaf pruning may damage the plant causing it to wither or develop poorly shaped leaves. When lateral buds are not growing on an already pruned branch, bud pruning is resorted to, for salvaging the branch.
Ideal Time for Bud Pruning
Bud pruning on a deciduous tree is a straightforward process because of the annual growth cycle of new leaves making it easy to determine the bud removal time. In coniferous trees, the buds first emerged during Spring and then in early summer after the first pruning and hence bud pruning needs to be done twice a year. The ideal time for bud pruning is early spring when the buds first emerge and before the leaves come out. Buds will continue to grow all the way until autumn. Because of this dual pruning activity, buds have a short growth period resulting in smaller leaves. New bud growth should be encouraged by pruning the leaves.
Now some trees have an extended season of budding which can last from spring and autumn. For these trees, buds need to be monitored and pruned as necessary for the entire period of budding.
Special preparation is required in the winter to prepare for the following year's budding on coniferous trees. Most of the leaves need to be pruned away from well-developed buds, and more of the leaves should be retained on the weaker buds. This allows the tree to develop more uniformity.
Bud Pruning Precautions:
Bud pruning should not be done on a plant which is not healthy or one that has become weak after being reported. If the trunk or any specific branches need to be thickened, then avoid pruning the buds. The Bonsai should be well fertilized and watered before and after bud pruning as this can damage the tree.
While leaf pruning is done for deciduous trees, pinching is usually done for coniferous trees like junipers. By removing the tips of the growing needles, branch ramification is encouraged and helps the Bonsai in maintaining its compact design. Pinching should be done when the tree loses its shape due to excessive growth of needles. Often branches of coniferous trees have many new buds and this should be pruned back to buds that are growing in the appropriate direction. Using scissors to remove the growing needles will cause the foliage to die or turn brown and hence finger pinching is advised. Pinching is carried out in spring and early summer.
How to do Pinching:
To do pinching, the tip of the shoot or the new growth is held between the thumb and forefinger and carefully plugged away. At the same time with the other hand, the branch is supported to ensure that only what is desired to be removed is pulled off.
Pruning vs Pinching:
Pruning is done to shape the branch, change its direction and create a taper in the branch. All this is done by pruning back to a bud which is facing the direction that the tree has to grow and is usually done to a shoot which has saved internodes.
Pinching is done by removing the tip of a growing branch which shortens the branch and releases the buds behind it by supporting the dominance of the apical bud. The terminal bud manufactures a hormone called auxin which prevents the other buds from opening. When the terminal bud is pinched, the buds the terminal bud are free to open. Usually, 1 or 2 buds will open before a new terminal bud is formed which starts manufacturing the auxin hormone again and stop the process.