Just like the art of bonsai itself, the planting pots for bonsai originate from China. The ceramic qualities of certain epochs are still unmatched.
A yellow glazed pot (Tongzhi, Qing Dynasty)
A porcelain Faux Bamboo pot (Yongzheng, Qing Dynasty)
A bonsai without a basis is not imaginable. This time we're not talking about the nebari, but about the plant container, the pot. The well-known direct translation of the characters for “Bonsai” means “tree planted into a container”. Tree and pot are inseparably connected in this meaning. Bon and sai build an entity that meets and determines the physical demands of the tree as well as the aesthetical demands. The pot must allow the growth and the shape of the tree as well as limit it, in the same way as a frame limits the picture, but also brings it to its full effect.
Because of the high import prices of Japanese pots and the often inferior quality of the Chinese mass products, many enthusiasts seem to have given more attention to the tree and have neglected the pot. But now there also exist pots made by local potters which produce amazing quality but cannot sell at low prices because of the production process (handmade individual items). The many centuries of plant container tradition in China and Japan (the original countries of bonsai) have produced extremely refined and authentic works of art which we would like to take a closer look at.
A enameled pot (Qing Dynasty)
A Junyao pot (song Dynasty)
In this article which can only roughly outline the subject. We will try to show you a world which has become so fascinating to some people that they nearly forget the tree over it and start to collect only pots.
Like the art of bonsai, the origin of the plant containers is China. Without the slightest scientific knowledge of chemistry, e.g. in the 12th century, Chinese ceramists produced plant containers just by patient experimenting and improving. They achieved an amazing quality which can not even be matched with modern technology.
From the epoch on in which buddhism came to Japan (since 538 AD), the Chinese plant containers were coveted collector's items. In fact, until a few yars ago, before Japanese ceramists had developed very high quality pots, Japanese bonsai enthusiasts mostly preferred Chinese pots, especially antique (Kowatari) containers. The Japanese pots were normally used for bonsai of lower and medium quality. And even today there is a fundamental difference between both types of pots - the charisma of the Chinese containers. They impart a special feeling by their smooth shape and strong colours. Still today each Chinese pot is distinguishable, individual in colour and shape.
A major difference between Japanese and Chinese pots lies in the production method. The Japanese containers are, though handmade, shaped in a mould. The clay is pressed into a pre-shaped mould and the inside of the pot is manually shaped. The Chinese use an inside mould which only serves as a framework for the clay. The outside is modelled by hand, which allows for countless shapes and decorations.
The glazes produce their colours during the firing process by metal or wood ashes. Cobalt produces blue colours, copper produces green colour shades if the atmosphere in the kiln contains oxygen (oxidation firing). Red colours evolve when oxygen is burned up in the kiln (reduction firing). Iron produces colour shades from leather over brown shades to a nearly pure black. In a reduced atmosphere one can achieve the beautiful and treasured seladon colour, a green-grey or green-blue.
The clay can be classified in three categories: terracotta, stoneware and porcelain. The difference lies in the mixture of the components. Terracotta is fired at 950° - 1100° C, stoneware at 1100° - 1300° C and porcelain at 1350° - 1400° C or more. The clay shrinks sometimes more than 10% during drying and firing. The different ceramic materials are of different hardness. Terracotta does not reach the point of sintering, it does not get glass-hard, stays porose and can absorb water (for example the red flower pots). Stoneware however is fired nearly up to the point of getting glass-hard, absorbs no water and is therefore frost-resistant. Porcelain is totally glass-hard and reaches the greatest hardness, but also the greatest brittleness.
For the choice of a pot, the character of the tree is considered as well as its trunk diameter and height, colour of the leaves, flowers, fruit and bark, and the season in which the tree is most beautiful.
From a horticultural point of view, terracotta flowerpots are ideal if the plants are only potted temporarily. But they must be placed in frost-free locations for the winter. Terracotta is porous, which allows water to escape through the pores and air to get to the roots. Terracotta pots dry very quickly and must be watered more frequently in the summer than stoneware pots, but this also has a cooling effect for the roots. The disadvantages are: fragility, low durability and the necessity to repot yearly because of the buildup of salts due to frequent watering.
Stoneware however is a very hard material. It can be glazed and therefore has an enormous aesthetical range. As this material is watertight, you should pay attention to perfect drainage. Before potting the drainage holes should be tested by pouring water into the pot: the water should flow off completely. If this does not happen, the holes mus be rasped smooth with a file. Stoneware is the material for bonsai pots. They are available in the most diverse shapes, colours and sizes. This should make it not too hard to find the suitable pot for each special tree.
Porcelain pots are not used very often anymore for bonsai, except the special made mame and shohin pots, because most of them are decorated and distract the attention too much from the overall composition of tree and pot.
A blue and white pot (Yongle, Ming Dynasty)
Text kindly provided by BONSAI ART.
Photographs 1-7 kindly provided by Mr I. C. Su, Taiwan
Photographs 9-15 BONSAI ART AUCTION Japan
Translation: Heike van Gunst