Bonsai soil is a different type of stuff altogether than your typical potting medium or native soil. It’s like night and day. Potting Medium is really nothing more than peat moss, sand, and perlite. Sometimes makers will add vermiculite and a starter fertilizer. Native soils range from acidic to alkaline, rocky to clay, and everything in between. While some native soils may be ideal for bonsai trees, they all too often harbor diseases that can kill a plant.
This means that we must use a special soil for our bonsai trees with specific properties that allow water to easily drain through. Because the pot is small, if water stood for a length of time longer than several hours, it would promote root rot, stem rot, and other diseases.
The truth about bonsai soil is that it is based on the native soil in Japan. If you were to look at the soil in Japan, you would see a mixture of clay, sand, stone, and other debris. This specific combination is caused by the formation of the island by volcano’s millions of years ago. When broken up, the soil creates balls of clay and stone and leaves many thousands of air pockets per square foot. If you pour water on top of it, The water runs immediately through.
Bonsai Soil emulates Japanese native soil by providing a mixture of several ingredients which are large particles that allow good drainage. Some would say it also supports the tree in the pot and this might be true to some extent, but it does not have to be because we wire the tree into the pot. It’s the wire that actually holds the tree in the pot. The ingredients in bonsai soil are typically bark, small gravel, sand, akadama (clay balls), perlite, and a small amount of peat moss. Any soil that has particles large enough for the water to easily percolate through due to air pockets between each soil particle. While we do want water to easily drain and percolate through the soil, we don’t want soil particles so large that the water pours straight through. This would kill the plant just as easily as a soggy soil would.
We carry a high quality bonsai soil, akadama, which is little baked clay balls that hold water and don’t fall apart, and Kanuma, mined in the Kanuma region of Japan, is a version of semi fired clay balls for acid loving plants. This is a type of Japanese native soil that is scooped up, screen sorted, and kiln dried to sterilize it. All three of these soils are ideal to be used alone, or as a mixture.
When you use quality specialized soil with your bonsai, you will notice your plants are much healthier and happier. It’s a difference you can see.
Learn more about soil:
Read Now: Bonsai Soils and their Usage