History
It appears that the Chinese were the first to miniaturize container-grown trees around 200 AD. The art form may be derived from the practice of transporting medicinal plants in containers by healers. Its early focus was on the display of stylistic trunks in the shape of animals and mystic figures.
From China, the practice spread to Japan around the Heian period. During the Tokugawa period, landscape gardening attained new importance. Cultivation plants such as azalea and maples became a pastime of the wealthy. Growing dwarf plants in containers was also popular, but by modern bonsai standards the container plants of this period were inappropriately large.
The period term for dwarf potted trees was hachi-no-ki, "a tree in a pot." The term "bonsai" probably didn't come into use until the late 19th century during the Meiji period.
Aesthetics
Japanese School
The Japanese aesthetic is centred on the principle of "heaven and earth in one container", as a Japanese cliché has it. Three forces come together in a good bonsai: shin-zen-bi (真善美) or truth, essence and beauty.
Traditional subjects for bonsai include pine, maple, elm, flowering apricot, Japanese wisteria, juniper, flowering cherry, azalea and larch. The plants are grown outdoors and brought in to the tokonoma at special occasions when they most evoke the current season.
The Japanese bons are meant to evoke the essential spirit of the plant being used: in all cases, they must look natural and never show the intervention of human hands.
Techniques
Shaping and dwarfing are accomplished through a few basic but precise techniques. The small size of the tree and the dwarfing of foliage are maintained through a consistent regimen of pruning of both the leaves and the roots. Various methods must be employed, as each species of tree exhibits different budding behavior. Additionally, some pruning must be done seasonally, as most trees require a dormancy period and do not grow roots or leaves at that time; improper pruning can weaken or kill the tree.Most species suitable for bonsai can be shaped by wiring. Copper or aluminium wire is wrapped around branches and trunks, holding the branch in place until it eventually lignifies and maintains the desired shape (at which point the wire should be removed). Some species do not lignify strongly, or are already too stiff/brittle to be shaped and are not conducive to wiring, in which case shaping must be accomplished primarily through pruning.
To simulate age and maturity in a bonsai, techniques called Jin and Shari can be used. Jin is done by removing the bark in an area of a large branch or the trunk, while Shari is the stripping off of an entire branch. These techniques simulate scarring by nature and limbs being torn off. Care must be taken when employing these techniques, because these areas are prone to infection, and removal of too much bark will result in losing all growth above that area. Also bark must never be removed in a complete ring around the trunk as it will cut off all water and nutrient flow above that ring.
(Original Source : Wikipedia Encyclopedia, Other Photo Source : Google Images)
