Penzai is an ancient Chinese practice of growing small plants in pots. Penzai literally translates to "tray scenery", but loosely means potted landscape. The practice moved through Asia and eventually into Japan. Bonsai trees, a Japanese pronunciation of Penzai, became popular during the Heian period in 794 to 1185.

The tree is of no use other than decorative. It is supposed to be contemplative for the viewer and an exercise in effort and ingenuity for the grower. There is no food or medicinal purposes for these plants. There are also no large-scale landscapes. As a result, the practice of Bonsai is very narrow and focused on one or a few plants in a pot.

One of the oldest known living examples is a National Treasure of Japan. It is a five needled pine considered to be at least five hundred years old. It can be seen in the Tokyo Imperial Palace collection.

Most plant material can be suitable. If it is perennial, has woody growth, and remains small in containers, it can be used. It should also branch and respond well to pruning.

There are some favorites in this form though. These have characteristics that make them visually appealing on the compact scope of these miniature landscapes. These characteristics usually include small leaves or needles. Some favorites include ficus, because it is easy to grow, many of the evergreen trees, because of their unique wood textures and small needles.

Source materials can be found in many different places. Source material is what is used to begin the process. Bonsai are very difficult to start from seed. Most growers don't want to start from seed either because the ultimate goal is a mature and weathered appearance. It would take many, many years to achieve this, so most growers use source material that is already mature or partially grown.

The list of techniques used in creating one is long. These techniques are not necessarily difficult, but they can take a lifetime to master. Pruning the roots, branches and trunk are the first steps. This lays out the general shape of the tree. Leaf trimming further refines this shape. Wiring and clamping use rigid materials to train the growth in the desired shape. If the tree doesn't naturally conform to the desired shape, grafting can be used to insert a piece of growing foliage in a desired spot. Defoliation can be used when leaves are too large, and new small leaves are desired. Removing the bark from a branch or trunk to give the appearance of deadwood is also employed.

Bonsai trees are an art, a meditation, and a horticultural practice. There are thousands of years of history and culture behind this art form. They are beautiful living sculptures.