Bonsai is an Asian version of the ancient Chinese hobby of cultivating miniature natural trees. Unlike other penjing, which uses intricate traditional styles to create elaborate natural scenes in clay pots that resemble real plants, bonsai uses simplified techniques that foster a greater degree of naturalness and realism. You can think of it as a cross between a tree and a small garden or bush. The techniques of planting are very similar.
For centuries, bonsai has been cultivated with a tree species known as the Ficus Retusa. In the past few decades, however, the Japanese have begun to develop hybrid varieties that resemble the more common pines and cedars used in traditional bonsai planting. These new cultivars have a short, squat trunk, a broad green trunk with long, pendulous branches that resemble palms, and foliage that look more like that of a palm tree. It has been called the “genetically dwarfed” Chinese pines and cedars. These traits have caused the American bonsai industry to focus on these two plant species, with an emphasis on trees with needles that have been “hand picked,” rather than those that have been “bred” naturally.
One of the most distinctive traits of a bonsai tree is the way that its branches are groomed. The traditional technique for pruning involves sawing off sharp portions and leaving the rest of the branch intact. Today, bonsai growers use wire brushes and loppers to prune without damaging the rest of the tree. A new trend in bonsai care is to completely remove any and all branches from the tree, leaving the trunk free and smooth. This is sometimes referred to as “pruning without cutting.”
Another hallmark of bonsai culture is the use of what is called a silhouette trunk. This is a simple procedure: simply take a blunt end of wire, place it against the trunk, and twist it slightly. The result is a “skeleton” of a branch that resembles the silhouette of a tree when viewed from the ground. Branching is very limited in the Bonsai art, since the shape of the trunk is so important in determining the overall effect. In general, a simple back branch placed correctly in a Bonsai pot will add depth, width, and character to the tree.
There are two major artistic styles in Bonsai cultivation. The first is called “Shimen” or “Bamboo style.” This style is an exceptional hybridization between the classic garden of China and the miniatureaturization of Japanese artists. Its branches are arched, and the foliage is often very sparse. Because of this, the tree has a very small trunk and great potential for growth.
The second is known as “Shimen” or “Chinese elm,” and is the most popular and formalized of the Bonsai styles. The majority of bonsai styles that are developed using these roots are truly representative of Chinese elms. Branches of this size have a completely symmetrical appearance, and their leaves are rarely branched. Branches of this size may be very wide, nearly touching at either end, or they may be short and tapering. The trunk itself can be arched, but the appearance is typically very smooth, without any frills or sketchiness.
These two styles are not representative of the rest of the Bonsai world. They represent the most popular trunk styles and are used in both indoor and outdoor Bonsai culture. There are actually several other styles, but they are limited to trees with narrow trunks and upright growth habits. Examples of these types of trees include Chinese elm, crabapple, gardenia, kangaroo trunk, Japanese maple, bamboo, tamahagoda, and many more. You can find Bonsai books that will tell you all about the specifics of each Bonsai style, but in general they are narrow with upright growth, straight with pendulous foliage, and usually have an upright trunk.
The third type of Bonsai is called formal upright style, or commonly called formal upright stem. Unlike the other two, it is the only one without any branches. It will have a wide, shallow trunk, and its leaves will be completely parallel from side to side. The entire tree will be upright, with its branches rarely if ever spindly or tapering in shape. Formal upright style specimens often come in a variety of colors, and their foliage will be completely white, cream, silver, gold, or maroon. These types of Bonsai will rarely be pruned, because they have very strong roots and require strong roots for support.