WalMart, Home Depot and Amazon.com all sell small bags or containers of vermiculite, as of 2015. For larger quantities of vermiculite, visit a local greenhouse or garden center, or order it online from companies like Carlin Horticultural Supplies, 7 Springs Farm, Morton's Horticultural Products or Home Harvest Garden Supply.
Vermiculite is a phyllosilicate mineral with a wide variety of different uses. It is commonly used in horticulture and gardening applications as a soil conditioner in areas where the soil is heavy or sticky due to large quantities of clay. By mixing vermiculite into this type of soil, it creates air channels that allow the soil mix to breathe properly. It can also be added to sandy soil, helping it retain water.
Other common gardening uses for vermiculite include storing bulbs and root crops and as a soilless growing medium such as in hydroponic applications. It can also be used for germinating seeds, either on its own or mixed together with soil or peat. Using vermiculite for seed germination is beneficial as it requires very little watering.
Vermiculite also has a variety of industrial and commercial applications, including in the construction of swimming pools, as a loose-fill insulation. Moulded vermiculite boards and shapes are also commonly used in open fireplaces, acoustic panels and for fireproofing of structural steel and pipes.