Akadama is a premium bonsai soil used by Japanese master gardeners. Akadama soil is mined in Japan from volcanic soil. Once extracted its dried and sifted to various grain sizes.
A lot of our experienced customers use Akadama soil for their conifers and deciduous trees, but it’s also recommended for novice gardeners. Akadama soil changes color (it darkens) when wet, which provides a visual indicator of when to water your plant.
- Large Grain: Particles range from 1/4″ – 1/2″. Used for larger trees.
The exact mix of bonsai soil is dependent on what type of tree species is being used. That said, here are guidelines for two types of soil, one for deciduous trees and one for conifers. For deciduous bonsai trees use 50% akadama, 25% pumice, and 25% lava rock. For conifers use 33% akadama, 33% pumice, and 33% lava rock. Depending upon your region’s conditions, you may need to amend the soil differently. That is, if you do not check on the trees a couple of times a day, add more akadama or organic potting compost to the mix to increase water retention. If the climate in your area is wet, add more lava rock or grit to improve drainage. Sift the dust from the akadama to improve the aeration and drainage of the soil. Add the pumice to the mix. Then add the lava rock. If the lava rock is dusty, sift it as well prior to adding it to the mix. If water absorption is important, add organic soil into the mix. This isn’t always necessary, however. Usually, the above mix of akadama, pumice, and lava rock is sufficient.