This year we are asking MBS members to consider ordering soil components for next years’ repotting needs. We have found that ordering in the spring is often too late for most people. Based on previous orders, we estimate the costs for each item will be as follows:
– akadama (14L bag) – $27.00
– pumice(40# bag) – $25.00
– lava(40# bag) – $15.00
The order will only be placed to fill pre-orders, so please plan ahead in case there an order is not placed next year. An email will be sent when orders are ready, which would be in the fall of 2019. If you use a 3-part soil mix, recommended by most bonsai professionals, you would need about 2-3 bags of akadama per 1 bag each of lava and pumice. The yield of this after sifting and sorting to size is roughly three 5 gallon pails. It will take a few weeks to get the orders filled and shipped once we have reached the necessary quantities.
Akadama (赤玉土 akadamatsuchi, red ball earth) is a naturally occurring, granular clay-like mineral used as soil for bonsai trees and other container-grown plants. It is surface-mined, immediately sifted and bagged, and supplied in various grades: the deeper-mined grade being somewhat harder and more useful in horticulture than the more shallow-mined grades. Akadama may also act as one component of growing medium when combined with other elements such as pumice or crushed lava. Akadama’s color darkens when moist which can help the grower determine when to water a tree.
While akadama is more costly than alternative soil components, it is prized by many growers for its ability to retain water and nutrients while still providing porosity and free drainage. For all of its qualities, many bonsai growers consider the cost of akadama prohibitive or unnecessary. Still other growers claim that when subjected to cold and wet climates, the granules progressively break down into smaller particles which inhibit drainage, an essential characteristic of bonsai soil. This problem can be avoided either by incorporating sand or grit in the soil mix, or by using the deeper-mined, harder grades.