How to Use Perlite to Improve Soil and Boost Plant Growth
1/4 inch to 3/8 inch. Fine perlite. #1. 1/8 inch. Super coarse and coarse perlite: This type of perlite is often used to amend raised beds and garden beds, or dense soils with high water-holding capacity (clay). Size #4 perlite is a whopper of a particle that should only be used for extremely heavy soil.