Bonsai is a horticultural art unique to Japan whereby grasses and trees are transplanted into small earthenware containers and are grown into desired shapes. Although there are many different plant varieties, the pine, maple, plum, and azalea are particularly common. Care for bonsai consists of selecting the appropriate type of soil, use of fertilizer, periodical repotting, wiring the branches or trunk to control the shape, and pruning. A period of one or two years is not enough to allow bonsai to grow into the right shape. Bonsai takes many years, sometimes decades of nurturing.