Medium Sponge Rock
Sponge rock, also known by the name Perlite, is a very common ingredient in orchid mixes and for good reason. Sponge rock decreases compaction of mix, increases aeration and retains moisture. Sponge rock is a volcanic glass that expands when heated and becomes very porous. Medium sponge rock, #3, is the perfect size for a wide range of mixes and is a component in our general purpose orchid potting mix.
See also:
Home
