Particle Size: Typically, particles are larger than 1/2 inch (12.7 mm) in diameter. Texture: Noticeably coarse, with a more uneven texture compared to other sizes. Applications: Commonly used for specialty horticultural purposes, especially for orchids and other plants that require superior drainage and air circulation. It can also be used in stormwater filteration systems.
For gardening, look for horticultural perlite, which can be large to medium grade with 1/2–inch—1/8-inch particles. Coarse grade or extra-large perlite with particles larger than ½ inches is perfect for orchids, succulents, and other plants that require good drainage. In construction, perlite is added to plaster or mortar to lighten them ...