Horticultural Clay commonly referred to as calcinated clay, calcined clay and turface. Like Akadama this clay is mined and heated treated but unlike Akadama, Horticultural Clay is heated to a much higher degree and will not break down. Horticultural Clay is relatively new to the world of Bonsai, but a quick search online will show just how highly regarded it is as an addition to Bonsai soil and sometimes as an economical substitute for Akadama. While Akadama has been used for hundreds of years if not longer in the art of Bonsai, it was locally available to Bonsai artists developing the living art form in Japan. Many Bonsai artists in North America have been searching for years for a local substitute for Akadama.
Horticultural Clay has been found to be an excellent solution, offering the same qualities as Akadama. Excellent moisture and nutrient retention, preventing soil compacting and helping aerate the root system while being PH inert.
This Horticultural Clay is offered in both 1 and 2-pound bags and can be used as a 1:1 substitute for Akadama.
For Tropical trees, we recommend the following mixture:
2/3 Base Substrate Mix and 1/4 Horticultural Clay
For Coniferous Species we recommend the following mixture:
For Deciduous Trees we recommend the following mixture:
1/2 Horticultural Clay and 1/2 Base Substrate Mix