I'm not positive, but you should be able to get it at Peavey Mart, if you live near one.

Personally, I wouldn't bother. I did square foot gardening years ago, and had great results without using vermiculite.

Thanks, I don't live near a Peavy Mart, but in Winnipeg I found it at St Mary's nursery in the large bags. I was too late though, my experimental square foot gardern is already in and I already put in some lettuce. I used a mixture of different composts, peat and coir. Should work