Each year, in the Spring, Whole Foods here in Boulder gives away two very large burlap bags of compost to anyone that shows up. The compost is a finer dust than any sand and the bags don't seem to leak it much. All the bags seem to have some sort of coffee brand on them. I have no idea where they get them, but if you want to give them a ring to ask where the 'Spring burlap compost bags' come from, their phone number is 303.545.6611