Volcanic glass that has been heated until it “pops” like corn, resulting in a lightweight, porous and stable material. Widely used in potting mixes (usually as 20–25% of the total mix) to improve water retention and prevent compaction. Our OMRI-approved perlite is classified as Super Coarse, meaning it has been screened to remove finer particles.
Also used for rooting cuttings: place cuttings in a plastic bag of moistened perlite with the cut ends buried up to the node, then fill the rest of the bag with air, seal, and leave in indirect sunlight for two to three weeks.