There are many raw materials used in soilless cultivation media. Soilless cultivation media are professionally referred to as Growing Media. Sometimes the raw materials are used on their own without mixing with other raw materials, e.g. in slabs of coir, wood fiber or stone wool. Quite often though, raw materials are mixed into a blend, with the blend being the desired growing medium.

Just to give an impression, raw materials include:

• Natural mineral materials like pozzolan (volcanic origin), zeolite (a clay material) and sand (sedimentary origin).
• Man made mineral materials like stone wool, perlite and glass foam.
• Organic materials like peat (a non-circular “fossil” matter), wood fibers and coir products (from processed coconut shells).
• Man handled organic matter like composts, digestates and fermentates.
• Man made organic materials like foams, super absorbing gels and fibers. These used to be oil base (non-circular) but all are presently offered as biobased biodegradable synthetics.

Each of these materials and blends thereof produce a unique set of physical, chemical and biological properties. The physical properties include water characteristics, root support and root resistance. The chemical properties include nutrient content, pH buffer capacity and ion exchange properties. The microbial properties include degradability, nitrogen immobilization and microbial and fungal abundance.

In the sub menus of this page you will find descriptions of many soilless cultivation media. These descriptions are split in two parts.

The first part describes the processing of the raw materials needed to make them suitable for various applications in the field of greenhouse cultivation. The purpose is to allow the reader to evaluate the restrictions and possibilities of the production process on the properties needed for the application. The second part describes the material as found in cultivation. This part focusses on the interaction between roots, growing media and the microbial and non-microbial life.

At present, December 2024, there are descriptions of:

• Stone Wool Production
• Wood Fiber Production