What keeps a bonsai small?
From BonsaiWIKI
One point about bonsai is the paradox that they are quite small but often reflect great age.
Like most trees, bonsai continue to grow throughout their lives; however, the growth of a bonsai is regulated by several factors:
1. Plants grown in bonsai containers tend to grow more slowly than those that are planted in the ground. Most bonsai if planted in the field and properly maintained would rapidly lose their dwarfed characteristics and grow into a full-sized garden trees or shrubs. Bonsai containers place physical limits on the growth of the root system, which in turn limits the development of the portion of the tree above the bonsai soil. In extreme cases the tree may become rootbound.
2. Bonsai are trimmed periodically to maintain their silhouette and to shape their branches in an aesthetically pleasing way. By doing this, the bonsai artist is making the tree smaller, but what makes the tree a bonsai is that the careful pruning that is used trains the tree to have the same visual cues that the viewer is used to seeing in large landscape trees. Among these:
- A distinct trunk that divides into increasingly smaller branches
- boughs of foliage, separated by space
- Foliage arranged in a canopy
- Attractive surface roots
These same trees planted in the ground might have a shrubby or rangy appearance, but when cultivated as bonsai, the bonsai artist can develop the graceful forms of a mature landscape tree and impress that appearance on a tree that is often much younger in age.
Plants grown in containers tend to have smaller leaves and internodes, and these characteristics can be further emphasized by periodic pinching of new shoots and reshaping.
In this way the paradoxical illusion of a miniature tree is created.
