Replaces conventional potting soil. This breathable natural product is ideally suited for hydroponics, green roofs, and tree planting due to its salt content and water-regulating properties. The natural clay is fired in a kiln, resulting in a ceramic surface and a core filled with countless air pores. As the clay expands during this process, it is also referred to as expanded clay. Plant clay retains water and releases it to the plant in a regulated manner. It is inorganic and purely mineral - no rotting, no decay or decomposition, and completely odorless. Perfect conditions for all plants in the home, garden, parks, and professional plant cultivation! Also suitable as winter mulch.