Bonsai Tree Pot
All kinds of containers are used for training pots: clay saucers, plastic containers, and wooden boxes of many different sizes. The Bonsai tree pot should be just large enough to accommodate the tree’s root system.
Generally, bonsai tree pots come in five shapes: round, oval, square, rectangular, and hexagonal. In each shape there is a wide variety of sizes.
Trees trained in the cascade and semi-cascade 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.
The color of the Bonsai tree 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.
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.
At the end of the first year, the tree is usually transplanted from its training pot (or from the ground) into a pot suitable to its dimensions.
Retain some of the original soil, and trim the roots if necessary. Cut away any abundant growth of new roots at the base of the trunk before repotting.
If only a few roots have formed around the taproot, prune these roots slightly. Prune the taproot again at the end of the second year, and cut it short at the end if the third year. This final cutting should be done when the new roots have appeared at the base.
Repotting of bonsai plants is usually needed when soil insects damage the plants, or when soil is in poor condition.
Sometimes, however, a soil condition can be corrected without repotting and disturbing the roots of the plant. This is done by adding new soil around the outer surface, or by removing plugs of soil and replacing them with a free-draining soil mix.
A healthy bonsai puts out new surface roots every year. The growth of these roots makes it difficult for vital water and air to penetrate the soil.
The surface roots will be nourished but the main root near the trunk will die. Therefore, periodically cut back the main root and thin out the surface roots.
A tree’s rate of growth determines the frequency of repotting. Pines and spruces, for example, need repotting only once every 3 to 5 years; flowering and fruiting trees, every year or — depending on the variety— every second year.
Repot quick-growing species, such as willow, at least twice a year. Repot your plants in the early spring when the first new buds appear.
When the tree is in a dormant state it is unable to establish itself in the new soil and root diseases are likely. For this reason, bonsai must never be repotted in winter, except when kept in greenhouse culture.