Containers suitable for Bonsai fall into two main categories: the training container and the display pot. Training containers are used when the tree is in an early stage of development and can be anything from a plastic seed tray to a wooden box treated with a harmless preservative. All sorts of improvisations are possible provided that the container has adequate drainage holes and no undulations in its base to trap water. This is absolutely vital as the major cause of bonsai fatalities is due to root rot resulting from waterlogged pots.

In the early stages it is usual for trees to be planted in over-sized containers. This will encourage better root development which is essential if the tree is to be sustained in a healthy condition.

Display pots are invariably ceramic and, because they must be frost proof, stoneware pots are preferable to earthenware pots. Use only pots that have been glazed on their outer surfaces as roots tend to grip unglazed pots better.

Display pots should always be considered and chosen to suit the Bonsai and not the other way round - rather as a picture frame is selected to compliment a picture. The pot, however fine or precious, should always take second place to the tree and should enhance the display rather than dominate it. Apart from the aesthetic considerations, the pot also has an important practical function to perform. It holds the nutrient-rich composts made up from various soil ingredients, fertilisers, air and moisture and also serves as the stabilising foundation for the tree within it. Generally the pot’s length is about two thirds the height of the tree (if a tall tree), and similarly two thirds of the width if a spreading one. The depth of the pot approximates to the thickness of the trunk just above the root crown. This proportion of pot to tree will usually satisfy both aesthetic as well as horticultural requirements.

Obviously, pots containing cascade-style trees need to be considerably deeper. It won’t be necessary to find your ruler; instead, train your eye to discern a balanced relationship between pot and tree. Bonsai by measurement is too formulated, and it’s practise is anathema to any self-respecting artist.

Never be in a hurry to plant the Bonsai in its display pot. Always make sure that the major training regimes are achieved whilst the tree is still in its training container.

Muted colours are generally preferred for display pots whether they are glazed or not, but the ‘wee’ pots used for ‘mame’ Bonsai (very small Bonsai never more than six inches 150mm including pot) and for some flowering and fruiting trees can be somewhat brighter and decorated. Conifers are best displayed in unglazed pots bordering on the umber, grey and dull Indian red shades. Deciduous varieties on the other hand, often look well in pots that have a subdued glaze and these can be especially pleasing if a crazing is evident in the glaze and when variations in the texture and colour of the glaze are also present. Pots that exhibit interesting flaws in their glazes tend to be preferred to pots that are superficially perfect and lacking in character. Avoid pots that look like ovenware.

Choosing the right pot for the tree is a fascinating exercise in its own right, and an harmonious marriage of Bonsai and pot is an image to be savoured.

Extract taken from ‘The Bonsai Book’ Ebury Press 1989