This section covers the special needs of bonsai in regards to its soil, also known as substrate, and the many components to provide the required characteristics.
Components and their purposes
Bonsai soil components have two major tasks, to provide food and water.
Modern practices dictate that Bonsai soil should be well draining, moisture retentive, and allow aeration. To achieve this, inorganic components are often used. These can include:
Akadama - Widely used in Japan, and available in the west, albeit at higher prices due to transoport costs. Akadama has excellent attributes, but breaks down easily if allowed to freeze. If so, it can renewing every year or two .
Kanuma - Similar attributes to akadama, but suitable for acid-loving plants such as azaleas.
Diatomaceous Earth - A fired clay product being used more frequently in recent years. Sold in Europe as certain brands of cat litter