Perlite or sponge rock is the name of a naturally occurring mineral. In nature, it exists as a type of volcanic glass, created when the volcanic obsidian glass gets saturated with water over a long time.
Perlite is used in mixes to improve aeration and modify the soil substructure, keeping it loose, well-draining, and defying compaction.
- Perlite is physically stable and retains its shape even when pressed into the soil.
- It has a neutral pH level
- It contains no toxic chemicals and is made from naturally occurring compounds found in soil
- It is incredibly porous and contains pockets of space inside for air
- It can retain some amount of water while allowing the rest to drain away