Containers for Bonsai
Most plant material for bonsai has long roots that will not fit into a bonsai container. For this reason a training pot is used. The training pot is larger than a bonsai container and holds the heavy roots, which are gradually cut back, for a period of years until small, fibrous roots develop.
All kinds of containers are used for training pots: clay saucers, plastic containers, and wooden boxes of many different sizes. Many of these clay and plastic pots are available at garden centers. The azalea pot and the bulb pan are especially suitable. The pot should be just large enough to accommodate the tree's root system. It should be similar in shape to the bonsai pot which will eventually replace it.
For example, an upright tree, destined for a low, flat container, should be grown in a fairly low training pot. A cascading tree, to be planted later in a high bonsai pot, should be trained in an ordinary flower pot.
Make sure that all training pots you use have drain holes at least 1/2- inch in diameter.
Choose a pot in which to display your bonsai when the training of your bonsai is sufficiently advanced. The size and shape of this pot will depend on the size and shape of the tree.
Trees trained in the cascade and semicascade styles look best in round or rectangular pots. Plant the trunk in the center of the pot with the branches sweeping down over the side.
Place upright trees slightly off-center (one-third the distance from one end) in oval or rectangular pots. Place trees with thick trunks and dense foliage in deep, heavy pots.
Branches of a bonsai should harmonize with the shape of a pot. If the branches are longer on one side than the other, place the trunk off- center in the pot.
The color of the pot should contrast with the tree's foliage. Use white, tan, or green pots for trees with brightly colored flowers or fruits. Use unglazed pots with pines and deciduous trees.
Generally, bonsai containers come in five shapes: round, oval, square, rectangular, and hexagonal. In each shape there is a wide variety of sizes.
Bonsai containers can be obtained from some of the larger nurseries. Chinese or Japanese hardware stores, and stores that specialize in imported items, also offer containers.
Bonsai plants must be anchored to their containers until the roots take hold. One method used to anchor the plant is to tie it down with wires leading up through the screens that are placed over the drainage holes in the container. After tying the plant to the container, adjust the plant's elevation.