Bonsai soil, recommended mixtures

Using the right soil mixture for your Bonsai trees is crucial. Soil is important to supply your trees with nutrients, but it also needs to drain properly, provide enough aeration and retain water. Though most (online) Bonsai shops sell ready-mixed soils, doing this yourself will save money and lets you adjust mixtures per tree-species.

 

Bonsai soil components
The most important components for any bonsai soil mixture are Akadama, organic potting compost and fine gravel (grit).

• Akadama is hard-baked Japanese clay, specifically produced for Bonsai purposes and available at all (online) Bonsai shops. It needs to be sifted before using it. Keep in mind that after about 2 years akadama starts to break down, significantly reducing aeration. This means that regular repotting is required. Akadama is rather expensive and is therefore sometimes substituted with similar fired/baked clays that are easily available in any garden center. Even cat-litter can be used as a substitute, check our bonsai forum which brand is recommended in your country.
• Organic potting compost includes pea moss, perlite and sand. It has several disadvantages (it retains much water and doesn't aerate/drain very well), but as part of a mixture it can be used perfectly well.
• Fine gravel / grit is of great importance to create a well draining and aerated bonsai soil. It is also used as a bottom layer in Bonsai pots to enhance drainage a bit further.

 

Left: Akadama   Right: Potting compost

 

Left: Grit   Right: Mixed Bonsai soil

 

Recommended soil mixtures
Different tree-species demand different soil-mixtures, so make sure to check our tree-species bonsai guide to find the optimum mixture for individual trees. We can however describe two main mixtures, one for deciduous trees and one for coniferous trees. Both mixtures consist of Akadama (to provide the mixture with aeration, drainage and medium water retention), organic soil (nutrient rich, water retaining) and split (drainage).

Note that both mixtures can, and should, be adapted to your local circumstances. When living in a relatively wet climate, use more grit/akadama.

 

Deciduous tree bonsai soil

• 50% Akadama
• 25% Organic potting compost
• 25% Grit

Coniferous / Pine tree bonsai soil

• 60% Akadama
• 10% Organic potting compost
• 30% Grit

 

 

More information
Check the species specific guidelines on soil for Bonsai trees.
Go to the repotting and bonsai soil forum or check our general Bonsai care guidelines.
Check the Bonsai soil video.