MULTIPLE USES: Cacti, bonsai, succulent containers, and potted plants SMALL GRAVEL SIZE - Lava rocks vary in size from 1/4" to 1/2" in diameter 100% NATURAL - Pure volcanic rock with no additives, dyes, or fillers PROTECTS PLANT ROOTS - When placed at the bottom of the planter, lava rocks create a place for excess water to pool away from your plant's roots AIDS WITH WATERING - Lava rocks are naturally porous, they can absorb and slowly release excess water over time Midwest Hearth lava granules for plants are 100% natural pure volcanic lava rock with no additives and have an average granule size of 1/4" to 1/2" in diameter. Place in the bottom of your planter to help excess water pool away from your plant's roots.