Try your local plant nursery.

Try a garden centre, or a Homebase store

Try your local garden center or greenhouse.

You can buy this at a hardware store, such as menards or home depot, lowes. It is used as insulation. it comes is big bags when you buy it this way. it is virtually the exact same thing that you would buy at a garden center, or online for a fraction of the price. Pearlite also serves the same purpose (water retention). Pearlite is also natural and fairly innexpensive. But I would go check out your local hardware/home improvement store and check out your options.

Hello you can by vermiculite at agway in endicott or agway in binghamton. Hope this helps