Perlite (smaller chunks than Sponge Rock, but of the same material) is a naturally occurring, mixed glassy silicate of volcanic origin which 'pops' when furnaced. Its unique internal structure consists of numerous tiny closed air cells surrounded by a large exterior irregular surface. Expanded Perlite is ultra-lightweight, inert, sterile, permanent, incombustible, asbestos- free, non-toxic, rot and vermin proof and has a neutral pH. Its extremely large, open surface area allows it to retain water in mixes while maintaining air spaces, important for healthy root growth.
We use Perlite as part of our Fine Orchid Mix.
We Also Recommend