To prevent a tree from being pot-bound and ultimately starving to death, regular repotting is crucial. Re-potting your Bonsai will not keep it small; instead it will supply the tree with new nutrients that it needs to grow and flourish.
How often should I repot?
It depends on the size of container/pot and tree species how often a Bonsai needs to be repotted. Fast growing trees need to be repotted every two years (sometimes even every year), while older, more mature trees need to be repotted every three to five years. Do not repot on a routine, instead check on your trees every early spring by carefully removing the tree from its pot. A Bonsai needs to be repotted when the roots circle around the root system. When the roots are still contained in soil wait another year before checking again.
This tree needs to be repotted as the roots circle around the root mass.
Repotting work normally needs to be done during the early spring; when the tree is still in dormancy. This way the somewhat damaging effect of repotting on a tree is reduced to a minimum, as the tree does not yet have to sustain a full-grown foliage. Repotting in early spring will also ensure that damage done to the root system will be repaired soon, as soon as the tree starts growing.
Bonsai soil mixture
Choosing the right soil mixture is crucial for the health of your trees, it should be draining enough to prevent the roots from rotting, while absorbing enough water to supply the tree with water. Although some tree species need special soil mixtures, the following mixture is suitable for most trees:
Mix Akadama, pumice and lava rock together in a ratio of 2:1:1. When you do not have time to water your trees regularly, choose a more water absorbing mixture (use more Akadama), while you should choose a more draining mixture (use more lava rock) when living in a wet climate. Read the Bonsai soil article for more detailed information on soil mixtures.
Choosing the right soil mixture is crucial for the health of your trees.
Choice of Bonsai pot
Choosing a pot that fits your Bonsai, both in size as in style, is crucial for the composition. For more information, check the Bonsai pots article.