There are numerous types of decorative mini trees. We show how and when to prune bonsai correctly and what to look out for with the different shapes and varieties.
Pruning a small tree as a bonsai - the Japanese art form of tree design needs to be learned and has its pitfalls. But even beginners can learn how to cut properly. We will teach you the basics, i.e. everything about the first cut, care, leaf and root cut and when it is actually time to cut back the bonsai. Following this article are useful guides for three popular bonsai species.
Pruning Bonsai: Basics
When cutting bonsai, a distinction is made between the care cut and the design cut. While the maintenance cut only preserves and refines the existing shape of the bonsai, the design cut serves to train the small tree towards its picturesque shape. Both are done by hand, as neither a small indoor nor a large garden bonsai should ever make the acquaintance of hedge trimmers.
A common misconception is that bonsai are special dwarf forms of their larger relatives. In fact, however, these are completely normal plant varieties that are kept small by small planters and targeted pruning. The biggest problem to overcome is always apical dominance. The Latin word "apex" means the top of something and apical dominance means the stronger growth of the shoot tips. This growth behavior is very important for trees and shrubs in nature, in order to grow quickly in height and width, in order to be able to absorb sunlight over the largest possible area and not be overshadowed by nearby competitors. Targeted suppression of apical dominance makes it possible to create miniature trees that appear to grow naturally.
When and how often should a bonsai be pruned?
The design cut is only performed if the shape of theBonsai should be redefined for the first time or afterwards. Because strong branches are removed and the overflowing of the cutting points means a lot of effort for the plant and a loss of water, the pruning is only done as needed and in early spring before the leaves sprout or in late autumn after the leaves have fallen - the same times apply to evergreen plants. In addition, the design cut should be limited to just one cut a year.
The pruning is always used when new shoots have emerged, i.e. very regularly and - depending on the plant species - almost all year round. The pruning constantly removes the shoot tips, which would otherwise suppress the growth of the lower shoots due to the apical dominance mentioned above. Regular maintenance pruning ensures even, dense growth - not just at the top, but at all levels of the plant along the shoot axis.
The right way to cut bonsai
Not every cut is the same. In the following, we explain the procedure for the care cut and the design cut in detail.
Care for Bonsai
Regular pruning is the real reason why the bonsai tree can be kept in its miniature form. It is possible and necessary during the entire growth period of the plants. With a pointed, sharp bonsai scissors, only the shoot tips of the newly grown shoots are regularly cut off individually. You can also remove whole new shoots if they don't fit into the overall picture.
But be careful with conifers like Pinus (pine) or Larix (larch): They are not cut with sharp scissors, but “pinched”: the tip of the shoot is twisted off or torn off with tweezers or pointed fingers, because the use of scissors leads to brown needles and is poorly tolerated by the plant .
It is important that only the soft, freshly grown shoots are removed in the care cut - larger cuts are better postponed to a suitable date for the design cut.
Tip: Leaf cut
Foliar pruning can be performed on deciduous trees in early summer and aims to produce smaller leaves and encourage branching. Small leaves simply suit the scaled-down form of the plant better. When cutting the leaves, all or just a part of the leaves are removed down to the petiole.The newly sprouting leaves are smaller in size. However, not all deciduous trees tolerate pruning and only he althy plants that have not just had to undergo repotting or pruning should be subjected to it.
The design cut of bonsai
The design cut in combination with the wiring forces the bonsai tree into the shape desired by the designer. Bonsai created from seedlings or cuttings are first pruned after a few years of normal growth - albeit when they are relocated to their relatively tiny bonsai pot. Now the future bonsai comes into contact for the first time with a special soil for bonsai, which was not absolutely necessary before. This first cut and all subsequent trimmings are usually done in early spring or late fall and in no case more than once a year.
Even decades-old, tall wild plants can become a picturesque garden bonsai with careful treatment and an annual pruning.
During the shaping, strong knots are also removed. Clean work with the right tools - concave pliers if possible - and the use of a wound closure paste are important in order to promote overflow of the resulting wounds.
Your individual creativity is required when designing your bonsai - you decide which shape Your artwork will have later. Deciding which branch to keep and which to remove is not always easy. That's why we've listed a few important basic rules for the design cut for you, which you can work your way through.
- First remove all dead branches and twigs as well as annoying dead leaves to have a clear view of your sapling.
- Vertically growing, strong branches, which can no longer be corrected by tying down and wiring, must be removed.
- If two branches arise from the same trunk at the same level, decide on one and remove the other.
- Remove one or more branches when they cross.
- Leave thicker branches at the bottom than at the top - this creates a natural-looking crown.
- Now remove all the branches that you don't think "fit into the picture" - you should always consider the view from all perspectives in order to get an all-round aesthetic shape.
Tip: cut bonsai roots
Quite a few bonsai experts advise shortening the roots after trimming. This seems logical, since the plant would otherwise sprout all the more after the pruning in order to restore the correct relationship between root and shoot. However, if the roots were reduced at the same time, this reaction is somewhat slowed down. In any case, it makes sense to carry out the design pruning together with the obligatory root pruning when transplanting. Incidentally, the use of suitable special soil for bonsai is of the greatest importance when repotting the bonsai. This ensures a balanced supply of water and oxygen to the plant roots so that they can grow optimally and remain he althy.
The right cut for every bonsai variety
To give you a good orientation, we present three types of bonsai and the appropriate pruning techniques. For this purpose we have selected a houseplant from warm climates, a coniferous tree and a deciduous tree.
Pruning Ficus as bonsai
Various types of figs (Ficus) can be grown as bonsai. The following applies to all of them: If you want a strong trunk, you can let the Ficus grow freely for two years at the beginning of training, because it tolerates the radical pruning that is then necessary without any problems. Subsequent regular pruning is essential - otherwise the tree will quickly lose its shape again. At the latest when six to eight new leaves have emerged on a shoot, a new care cut should be carried out. Some species form inappropriately large leaves, but because the Ficus species tolerate pruning well, the leaf size can be easily adjusted. The happily growing Ficus regenerates well and also sprouts out of the old wood, but large cuts should be treated with wound sealing paste.
Pruning pine for bonsai
Several types of pine (Pinus) are also suitable for growing as bonsai. For their pruning, it is important to know whether the respective species shoots new needles once or twice a year: species with two shoots per year are in early to midsummer on the newly emerged shoots ("candles"), except for a few needles shortened. Furthermorebuds higher up on the shoot are cut at the top to provoke them to grow out in the second shoot. If the second shoot has happened in autumn and is mature, superfluous shoots can be removed. This includes, for example, all but two if a large number of shoots arise from a single point, and shoots that grow vertically are essential. Finally, the growth potential can be slowed down by plucking out old needles.
In the case of species with only one shoot per year, the newly formed candles are only slightly shortened in early or midsummer, and surplus shoots can also be selected. Above all, vertically growing shoots should be removed. The old needles of these pines can also be plucked out in autumn to slow down growth.
Tip: Only the species Pinus thunbergii (Japanese black pine) and Pinus densiflora ( Japanese red pine) sprout twice a year. All other species are limited to one budding per year.
Pruning maple for bonsai
The often picturesque growing maple bonsai (Acer) should be pruned with care. Although it is possible to cut shoots and small branches all year round, a formal cut should definitely be made in autumn or summer in order to avoid excessive water leakage ("bleeding") and still promote rapid overflow. Acer is susceptible to fungal diseases, so a wound sealant should be applied promptly whenever possible. The somewhat sensitive maple only tolerates a leaf cut in summer every two years - or even annually if only part of the leaves are removed. It is a good idea to remove leaves that are noticeably large or to defoliate areas that are growing too vigorously in order to slow down their growth.
In this special article you can find out which fertilization your bonsai needs!
Many thanks to Floragard for the support!
