Akadama soil is dried red soil made from accumulated volcanic ash outskirts of Tokyo. It is characterized by being brown, grainy, and containing no fertilizer components. Therefore, there are few bacteria, and there is an advantage that disease is less likely to occur.

Known as one of the mainly used soils for horticulture and gardening. Especially suitable for bonsai and succulent plants. The ideal soil for plants is soil with air porosity. Akadama soil is the best material for creating air porosity structure in growing soil.