Bonsai trees aren't dwarf varieties. They're ordinary trees, kept small by art.
A bonsai can be made from almost any woody tree or shrub, with no special genetics. Pruning of branches and roots, wiring and a shallow pot keep it tiny while it grows to look ancient. One pine in the Tokyo Imperial Palace collection is thought to be at least 500 years old.
Bonsai, Japanese for 'pot planting', is often confused with dwarfing, the breeding of plants that are genetically small. Bonsai needs no such thing. Growers start from ordinary seedlings, cuttings, nursery trees or wild-collected specimens, called yamadori and often the most prized, and keep them small by confinement in a container combined with pruning of both the crown and the roots. Species with small leaves or needles and old-looking bark are especially popular because they suit the miniature scale.
The toolkit is precise: trimming leaves or needles, pruning trunk, branches and roots, wiring branches into position, clamping or guy-wires to bend them, grafting new buds or roots, and techniques called jin and shari that create deadwood to suggest great age. A cardinal rule is that the artist's hand should be invisible: pruning scars are hidden, and wires are removed or concealed so they leave no marks. Styles have names, from formal upright to cascade, raft and forest groups, usually planted in odd numbers.
The art came from China. From the 6th century, Japanese envoys and Buddhist students returned from China with container plantings, the forerunners of what the Chinese call penjing. A Japanese scroll from 1195 is the earliest known image there of dwarfed potted trees. Some bonsai from the 17th century survive today. The pine known as Sandai Shogun, cared for by the shogun Tokugawa Iemitsu and trained as a bonsai by 1610, is considered a national treasure of Japan.
Popularity spread from specialists to the public after 1800. By 1940 about 300 bonsai dealers worked in Tokyo, cultivating some 150 species and shipping thousands of trees abroad each year. After the war, Westerners began to train in Japanese nurseries, and today there are world conventions and dedicated museums, including the National Bonsai & Penjing Museum in Washington, DC.
Source: Wikipedia — Bonsai · Text summarised from Wikipedia (CC BY-SA 4.0)
