How to prune bonsai? A detailed guide to the latest bonsai pruning techniques
Bonsai uses plants, rocks, soil, water and other materials, and through artistic creation and horticultural cultivation, typically and intensively recreates the beautiful scenery of nature in a pot, achieving the artistic effect of shrinking a dragon to an inch and seeing the great in the small, while also expressing emotion through the scenery and conveying a profound artistic conception, just like a three-dimensional, beautiful miniature landscape scenic area. Now let us take a look at bonsai pruning techniques together!
Bonsai pruning techniques
1. Prune late, not early: It is generally believed that winter, when trees stop growing, is the best time to prune branches, and it is emphasized that one should “prune in winter.” This view is not comprehensive enough. To be precise, some tree species can be pruned in winter. For example, with crape myrtle, after short pruning in winter, the branches may look dry, but as soon as spring arrives, new buds will grow on the short branches. In fact, “spring pruning” is better than “winter pruning.” Pruning before trees bud in early spring, when the air temperature is a little higher and new buds will sprout within a relatively short time, means there is no risk of branches drying out. Compared with “winter pruning,” “spring pruning” has no other disadvantages either. For trees that bloom in spring, such as azaleas and plum blossoms, pruning must be done even later, after the flowers have finished blooming; otherwise, cutting off the flowering branches would defeat the purpose.
2. Prune thick branches, not thin ones: Some people pursue rapid shaping of bonsai and impatiently short-prune new branches that have not yet become woody, hoping to grow side branches again that same year and then prune again, pruning two or three times in one year to quickly form several levels of branch pads. The correct approach is to wait until the branch has become woody and has roughly grown to the intended thickness before pruning, so that the side branches that grow out will naturally form a better angle. One must overcome impatience. A branch intended as a branch pad must be allowed to grow to the intended thickness, generally at least one year, and if it is not thick enough, do not hesitate to let it grow another year.
3. Prune with fertilizer, not without it: After short-pruning a branch, if the branch pad does not sprout new buds for a long time, and even if it does sprout, the side branches do not grow vigorously, this is because of a lack of fertilizer. To encourage the branch pad to quickly produce strong buds and grow new branches rapidly, the amount of fertilizer used should be as much as possible on the premise that it does not cause “fertilizer burn.” In the peak growing season, one can alternate watering once and fertilizing once. But note that it must not be too concentrated. In this way, during the growing season with suitable temperatures, the side branches should grow continuously.
How to prune bonsai?
1. Keep branches and set pads: When cultivating a stump, branches and buds grow in clusters, and it is uncertain what to remove or keep, making it difficult to start pruning, or the conceived creative idea may be somewhat off, leading to incorrect pruning. Although this can be adjusted, it prolongs the time for developing branches and shaping, because setting pads is the prerequisite for the structural framework. According to the individual characteristics of the stump material, such as straight, slanting, curved, lying, hanging, or waterside, one should incorporate the author's conceived imagery, keep branches and set pads, remove all miscellaneous branches and superfluous buds, concentrate nutrients, and cultivate the retained branches, so as to enter the pruning and production stage as early as possible.
2. Coordinated pruning: When branch pads have grown vigorously, when to prune and where to cut should involve a comparison of thickness and length. This runs through the entire shaping and production of the potted tree and relates to every part of the potted tree's structural framework. Among these are the ratio between branches and trunk, the ratios among branch pads, and the hierarchical contrast between primary and secondary veins within a branch pad, all of which must be clear before pruning, with a well-thought-out plan and the intention formed before cutting, so that the cut is made and the branch falls exactly as it should.
3. Precise and detailed pruning: The angle of branches and buds, the direction in which branch forks extend, and the staggered irregularity among them reflect the extension, contraction, and turning of branch pads in space up, down, left, and right. If the angle is chosen improperly, although it can be remedied by wiring, it is still not as good as the natural state. Therefore, when choosing the angle of a bud point, one cannot consider only one aspect and ignore another. That is, regarding the direction of the branch, its spatial state, and its relationships with other branch pads, one must not only be clear but also plan “ahead” and make judgments, avoiding mechanical, rigid, and stereotyped results.
4. Integrated pruning: The outer contour displays the overall tree form of the potted tree, that is, what is commonly called a triangular or scalene triangular composition. Here, the length of individual branch tips should be subordinated to the whole, grasping points and lines while merging into the overall surface. Observe the whole, prune locally, and adjust comprehensively. At this time, the potted tree is basically becoming full and mature, and this belongs to the finishing stage of shaping and production. Its focus is on the length and opening-closing of branch pads and the overall relationship of the outer contour.
Bonsai pruning methods
1. Unbalanced pruning: Unbalanced pruning is not comprehensive pruning, but rather a local pruning method adopted according to the plant's physiological characteristics to benefit shaping and healthy branch growth and to avoid pathological branch dieback. It includes thinning pruning and branch control.
① Thinning pruning: Generally, when a new stump has survived and branches are retained and pads are set, excess branches are cut away without reservation, so that the retained branches receive ventilation and light while being supplied with concentrated nutrients, grow quickly and robustly, and shorten the time for branch pad cultivation.
② Branch control: Generally, in the initial stage of branch pad cultivation and shaping, due to the plant's phototropism, apical dominance, and various other reasons, branch growth is often unsynchronized, with some growing faster and some slower. To enable weak branches to develop and grow as quickly as possible, one must consciously trim back some branches whose proportions are relatively in place (cutting off most of the branch tips or side branches) to control them, so that weak branches can receive sufficient light and nutrients, lest individual branches remain immature and affect the pruning for the overall shape.
2. Balanced pruning: Balanced pruning is all-around pruning, generally when the potted tree is close to being formed or before exhibition. At this time, comprehensive pruning can be carried out repeatedly, not only making the branches mature and full but also maintaining the beauty of the tree form.
3. Pruning with leaves: Pruning with leaves means that the branch node retained by cutting must have leaves, especially the bud position determined for retaining a branch node must have leaves. If there are no leaves, the cut for that branch node should be extended to a leafy place. By forcing buds, after the retained bud position has sprouted normally, prune again to the proper position. This is due to the plant's physiological characteristics and the conduction role of the sap it contains. Therefore, as with unbalanced pruning, in general it must be done with leaves; otherwise, it may cause the cut to shrink or even the branch to die.
4. Reserved pruning: According to differences in tree species' wound-healing ability and special circumstances, during pruning, one may make reservations as a preventive measure, that is, not cutting to the final position in one go but cutting in two stages, leaving one to two extra bud positions, and pruning again after the retained buds have become slender, robust branches, or when the reserved node naturally withers. This method is often used in the pruning of species such as Chinese fringe flower and Chinese hackberry. In actual practice, thick branches have larger wounds and are prone to shrinking, so they can be left longer; thin branches shrink relatively less, so they can be left shorter.