Viagrow 4 cu. ft./29.9 Gal./113 l Horticultural Vermiculite (36-Pack)Viagrow Vermiculite is a natural soil amendment that promotes moisture retention and aeration in potting mixes and delivers vital elements to the plant roots resulting in better root development, growth rates and yields. Viagrow vermiculite can be mixed with Peat moss, mushroom compost, cactus soil, organic soil, bark, perlite, compost, coconut coir, worm casting, potting soil and just about any soil or soilless media. Viagrow Vermiculite #3 naturally