Training pot

A training pot is a simple, usually inexpensive container, often plastic or a large, low-cost ceramic pot, used while a bonsai is still being developed rather than displayed. Training pots are typically larger and deeper than the eventual bonsai pot, giving roots more room to grow and support faster trunk and branch development.

Keeping a tree in a training pot for several years after major structural work, like a trunk chop or heavy root pruning, lets it rebuild strength before being confined to a shallow, decorative pot that restricts root growth. Wide, shallow training pots are also used specifically to encourage nebari to spread sideways rather than down.

Moving a tree into a bonsai pot too early is a common mistake, since the smaller soil volume in a display pot limits growth right when a young tree still needs vigor to thicken its trunk and heal pruning cuts. Most trees spend years, sometimes most of their development, in a training pot before earning a place in a proper bonsai pot.