JARS v64n2 - How to Choose a Bonsai Pot
How to Choose a Bonsai Pot
Douglas Furr
Vida, Oregon"A person born to be a flower pot will not go beyond the porch." - Mexican Proverb
After our chapter hosted a presentation on the beauty and challenge of growing bonsai rhodies, I became interested in bonsai pots. I decided to figure out why they are so very expensive. And then I discovered that the more I learned, the more I needed to learn. The following is a synopsis of my discoveries thus far.
Bonsai containers are typically wood, plastic, mica, terra cotta, earthenware, stoneware, porcelain, and bone china. Plastic and mica are usually used as training containers. Mica pots are made of 80% mica (mineral), 15% polyethylene (plastic), and 5% graphite, and are an attractive, inexpensive choice if one does not intend to exhibit at shows. Terra cotta is not frost-resistant, and earthenware fired at a low temperature may not be frost-resistant. Thus, long-lasting bonsai pots of appropriate quality for treasured bonsai plants are glazed earthenware, stoneware, porcelain, or bone china, and that is why they are very expensive.
What distinguishes earthenware, stoneware, porcelain, and bone china from one another is the kind of clay used and the firing process. Earthenware is a course and opaque ceramic ware that is made of kaolin clay and fired at a relatively low temperature. It is always slightly porous, whether it is glazed or unglazed. If fired at a very high temperature, it is somewhat frost-resistant. From a horticultural perspective, it is good for a pot to be porous, so if you're not going to have your bonsai collection outdoors, earthenware may be the best choice.
Stoneware looks like earthenware, but is made of a higher quality kaolin clay and is fired at a higher temperature. Because of this, the strength and durability of stoneware is much closer to that of porcelain. It is impervious to water and absolutely frost-resistant. For these reasons, a stoneware pot, glazed on the exterior only, with a drain hole, is often considered the best choice.
Porcelain is made from a white, high-quality kaolin clay. Bone china is made from translucent white clay containing at least 25 percent bone ash. Both are fired at extremely high temperatures and are frost-resistant. However, the pots themselves may be artistically viewed as too "feminine" for displaying many types of bonsai plants.
Most ceramics are made following a few basic steps. The manufacturing process begins with dry clay, which is ground up and mixed with water. This is referred to as blunging. This mixture is blended to form slip, then pressed to remove excess water, placed into a pug mill and chopped, then cut and molded to shape, called leather, or cheese, then fired. The first firing in the kiln is the biscuit. The fired pieces are then glazed and fired a second time, which is the glost. Once polished, the pieces are complete.
Don't get me wrong, you can put bonsai plants into anything with a drain hole, but the suggested container is any container that does not compete with the beauty of the plant. Plain drab colors are better than bright flowery ones, and earth tones are highly recommended.
Sources
"A - Z of ceramics." Pottery and Ceramics. Stoke-on-Trent, North Staffordshire, England.
"Bonsai Mica Pots." Bonsai Beginner. Old Tree Bonsai.
"Selecting a Bonsai Container." Bonsaimonk.com. Bonsai by the Monastery.
"Differences in Ceramics." Best Of The Home.
Kres, Peter. "Basic Facts and Knowledge About Bonsai Pots." Bonsaipots.net.
"The Pottery Studio Glossary of Terms and Abbreviations." The Pottery Studio.
