Displaying a bonsai tree to advantage requires manipulating its component parts. Sometimes this manipulation is to keep the tree small, other times it is to create the illusion of a much larger, older tree or a tree with a distinct style. This is the artistry of bonsai at work.
Almost any tree, shrub or plant can be used for bonsai, but the best candidates are trees and shrubs that have small leaves or needles and are naturally dense or compact. Small leaves, a dense habitat and woody stems help maintain the illusion of scale, while temperate plants are the easiest to care for.
Refining the tree's structure starts with the roots. A portion of root visible at or above the soil line helps to create the illusion of age and weathering and is a desirable feature in bonsai. Exposed roots work with the trunk to produce an interesting composition. The trunk itself may be smooth or gnarled, creating character and drawing attention to its interesting features, but it should always have a smooth taper toward the top. The shape of a bonsai's trunk can be controlled through grafting and wiring, and while young, may be shaped to influence the structure of the tree.
Shaping is one of the fundamental tasks of bonsai cultivation. Beginning with a vision of the finished tree, the bonsai artist starts the long task of shaping the tree by carefully altering its branches. In bonsai design, a tree's branches provide symmetry to the whole and are manipulated through wiring and pruning to realize that original vision, both in scale and proportion.
This process can take many years, and in the case of some deciduous trees, requires the removal of all of the foliage from time to time. Wires can be left in place for a year or more and are carefully removed before they can score or harm the growing branches. Bonsai trees should always be balanced and harmonious. No branch should completely obstruct another. The aim is to fashion a tree in which each branch makes a contribution to the whole while never obscuring another branch. In this scheme, branch shape, root and trunk structure, and the color and shape of the foliage create a cohesive whole.
Now that you understand a little about cultivating bonsai, let's explore some things to look for when buying a bonsai tree.