Hoffman Horticultural Charcoal is a professional grade charcoal used for planting terrariums and containers. Horticultural charcoal encourages air circulation within the roots, and is ideal for planting terrariums and containers with or without a drainage holes.
Charcoal is a porous form of organic matter primarily composed of carbon. It is used as a soil conditioner to improve soil drainage. A layer of charcoal in the bottom of a container also acts as a filter to help remove chemicals, salts and other impurities which might be toxic to plant roots.