There are two basic considerations in choosing a bonsai pot – size and style. Is the pot big enough to accommodate my tree and its root structure in my climate? And how does it look with my style of tree?

Size considerations:

A Bonsai pot should be large enough to allow the current root system of your Bonsai tree to stretch its legs a little. The vital root ends should have enough room to draw nutrients and moisture from the soil. Whether you should repot your Bonsai in a larger pot or keep it the same size pot it currently in depends on the age of your tree, type of tree, how root bound your tree is and whether you’d like your tree to bigger or stay the same size.

Repotting doesn’t necessarily mean you have to increase the size of your pot. If you have an established Bonsai tree and do regular root pruning when you repot, your Bonsai in theory, can live happily in the same size pot indefinitely.

A very general rule of thumb is: the bigger the pot, the longer your tree can go between watering. In certain situations such as extreme heat and low humidity, it makes sense to consider a pot that is slightly larger than usual.

Style considerations:

Just as important as pot size consideration is the way your Bonsai looks in any given pot. The traditional, low profile Bonsai pot represents a slice of landscape featuring a majestic tree. The term “Bonsai” means “Tree in a tray”, so your bonsai pot size and shape should represent the natural surroundings that your style of tree looks best in. Most upright trees look great in a low profile pot. Larger pots are good for placement of a tree that is off-center where there is space for other features in your miniature landscape setting. They’re also good for multiple tree plantings, sometimes known as forest plantings.

Here are a few of the traditional rules of bonsai pot styles and size.

- In most cases the ideal length of the pot should be about 2/3 the height of the tree.

- If the height of the tree is shorter than its width, the length of the pot should be about 2/3 the width of the spread of the tree.

- The width of the pot should be a little narrower than the spread of the longest branches on both sides.

- The shape of the pot should relate to the style of the tree. Straight trunk style trees will balance better in a rectangular pot while curved or soft-lined trunk trees will look better in an oval, round, round cornered, or rectangular pot.

- A powerful and rugged looking tree should be planted in a similar looking pot. i.e. a pot with hard angles.

How do I know if it’s time to repot?

There are different schedules for different species of trees. Some need to be repotted every year and some can go for several years. A bonsai tree uses soil. It replaces the soil with roots and when the soil goes away the tree becomes root bound and has nowhere to go for nutrients and moisture. One of the easiest ways to know if your bonsai tree is ready to be repotted is to lift it out of its pot. Generally, if it comes out in a mass the shape of the pot… it’s time. If there is still plenty of soil and the roots don’t appear to be bound by themselves then you can go another year.