Bonsai is the Japanese pronunciation of a Sino-Japanese word. It is an Asian art form using cultivation techniques to produce small trees in containers that mimic the shape and scale of full size trees. Similar practices exist in East Asian cultures, including the Chinese tradition of penzai from which the Japanese version Bonsai originated, and the derivative miniature living landscapes of Vietnam. The Japanese tradition dates back over a thousand years.
The Japanese loanword "bonsai" has become an umbrella term in English, attached to many forms of potted or other plants, and also on occasion to other living and non-living things. According to Stephen Orr in The New York Times, "the term should be reserved for plants that are grown in shallow containers following the precise tenets of bonsai pruning and training, resulting in an artful miniature replica of a full-grown tree in nature. In the most restrictive sense, "bonsai" refers to miniaturized, container-grown trees adhering to Japanese tradition and principles.
The purposes of bonsai are primarily contemplation for the viewer, and the pleasant exercise of effort and ingenuity for the grower. By contrast with other plant cultivation practices, bonsai is not intended for production of food or for medicine. Instead, bonsai practice focuses on long-term cultivation and shaping of one or more small trees growing in a container.
A bonsai is created beginning with a specimen of source material. This may be a cutting, seedling, or small tree of a species suitable for bonsai development. Bonsai can be created from nearly any perennial woody-stemmed tree or shrub species that produces true branches and can be cultivated to remain small through pot confinement with crown and root pruning. Some species are popular as bonsai material because they have characteristics, such as small leaves or needles, that make them appropriate for the compact visual scope of bonsai.
The source specimen is shaped to be relatively small and to meet the aesthetic standards of bonsai. When the candidate bonsai nears its planned final size it is planted in a display pot, usually one designed for bonsai display in one of a few accepted shapes and proportions. From that point forward, its growth is restricted by the pot environment. Throughout the year, the bonsai is shaped to limit growth, redistribute foliar vigor to areas requiring further development, and meet the artist's detailed design.
The practice of bonsai is sometimes confused with dwarfing, but dwarfing generally refers to research, discovery, or creation of plants that are permanent, genetic miniatures of existing species. Plant dwarfing often uses selective breeding or genetic engineering to create dwarf cultivars. Bonsai does not require genetically dwarfed trees, but rather depends on growing small trees from regular stock and seeds. Bonsai uses cultivation techniques like pruning, root reduction, potting, defoliation, and grafting to produce small trees that mimic the shape and style of mature, full-size trees.