The art of bonsai, according to the University of Georgia, goes back to 14th century China, where dwarf plants were taken from nature and put into pots. The current version of bonsai is the cultivation of a miniature plant by keeping the roots and branches small, mimicking the appearance of a large tree in nature.
A bonsai tree is removed from the pot and all of its soil is removed by hand, and rinsed with water. The roots are trimmed so that there is a ratio of one shoot per root. The bottom of the bonsai container, which contains drainage holes, is lined with a 1/2 inch of gravel and soil. The bonsai is placed in the container and its roots are spread out and covered in soil.
According to the Cobb County Extension Service, bonsai soil should be quick draining and is loose enough for fine root development. Commercially bagged soil is often suitable. A home made soil mix of one part each clay, humus and sand creates the loamy soil a bonsai prefers.
The traditional bonsai is often curved at the top, and it is possible to train your bonsai in the same manner. A piece of copper wire placed at the crown of the tree and wrapped around the trunk to the top to bend the plant into the form you desire. Individual branches are bent in the same way.
Bonsai trees may require repotting up to twice a year, depending on the tree variety. Fast-growing plants such as crape myrtle and willow require repotting twice a year until they've matured. Pines, spruces and junipers, as well as other conifer plants, require repotting until the age of 3 to 5 years. During repotting the soil is changed and roots are cut back to stunt the tree's growth.
Pruning of the branches is required to keep the plant small. Leaves are removed to reduce the nutrient requirements of the plant. New shoots and buds sprouting from old shoots are pinched off of the plant back to a healthy node to reduce outgrowth. Daily watering is required to keep the small amount of soil the bonsai lives in moist, but not soaking wet. Application of a diluted, water-soluble fertilizer is recommended every two to three weeks.