10 things to do to prep your Bonsai for the growing season - Growing Mediums and SAkadama

Updated: Aug 16, 2021

The new growing season is upon us and time is running out to get everything we need. It can be a bewildering time with so much to decide but with this series we will look at all the necessary items we will need over this 10 part series.

Growing mediums and Substrates

For any Bonsai tree it all starts at ground level, the growing mix or "soil". If you get this part wrong then your tree will suffer from under or over watering and even nutrient deficiencies.

We use the term growing mediums as this better defines what we use in Bonsai. Growing mediums is the material wherein trees develop their root systems. It is possible to be a single material only or a mixture of many different ones. The growing medium is chosen to give adequate aeration, water requirements and correct growth at the stage of development of your Bonsai.

Soil on the other hand is a mixture of organic compounds, like: minerals, gases, liquids and organisms that combined support life. The main difference between soils and growing mediums is that soils occur naturally and are known as top soil as well, where growing mediums are correctly managed media created to fill the needs of a plant, usually in a container. Using soil in a container or bonsai pot does not work due to its small surface area and compacts creating drainage and nutrient deficiency problems.

Characteristics of Growing mediums are:

  1. Drainage

  2. Aeration

  3. Water holding capacity

  4. Weight or density/texture

  5. Cation Exchange capacity (CEC)

  6. pH

  7. Soluble salts