Bonsai (bone-sigh) is Japanese for tree in a pot.
The practice of bonsai is sometimes confused with dwarfing, but dwarfing generally refers to research, discovery, or creation of plant cultivars that are permanent, genetic miniatures of existing species. 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.
However, simply placing a tree in a tiny pot does not make it bonsai. The grower must possess vision and skill to train the tree's foliage and guide its shape. This is done through pruning the roots to keep the tree small, wiring the branches, and using other techniques to make the bonsai tree take on the look of a mature tree in nature.
Bonsai also require special care because of the small amount of soil in which they grow. The trees cannot have "wet feet" so special bonsai soil is used which dries out easier than standard houseplant soil. But because there is so little soil, bonsai require frequent small waterings. A moisture meter can be used to let you know when the bonsai tree requires water.
Bonsai must also be fed nutrients in spring and fall. The three most important nutrients are nitrogen, phosphoric acid and potash, but chelated iron is also a good idea. It may be beneficial to rotate fertilizer brands since they each contain varying trace elements.
Trees that grow in nature enjoy humidity that is missing from an indoor environment. It is therefore recommended the bonsai pot sit in a shallow tray with water that can be allowed to evaporate in order to add humidity to the air surrounding the tree. A flat rock or pebbles should be placed in the tray under the pot so that the bonsai is not sitting in the water. Again, the roots of the bonsai tree should not be kept wet.
Sunlight is required for bonsai except under special circumstances, such as when they have just undergone extensive pruning or repotting. A southern, western or eastern exposure will be necessary inside the house so that the tree receives bright sun. If it cannot get direct sun you should select a bonsai tree that can grow in reduced sunlight, or plan to put your bonsai outside for several hours each day.
The goal with bonsai is to achieve the desired shape while balancing the growth above ground with the root growth. The process of shaping begins right away while the tree is very young, and continues while it matures. Small growth can be trimmed away with sharp scissors, but larger branches need a concave cutter which will not leave visible scars.
Some people use copper wire to train their bonsai tree. The wire is carefully coiled around the branches in the direction you wish them to grow. Once a branch is wrapped it is bent once into the final position. The wire should be snug without biting into the tree. Six to twelve months later, before the wire starts biting the bark, it is snipped away at each turn or coil so that it drops away. Uncoiling the wire without cutting it will damage the branch.
Some popular styles of bonsai include: formal and informal upright, cascade, windswept, slanting and forest, but there are countless variations and many more styles. In fact the only thing limiting the bonsai tree is the vision of the grower.
