A friend of ours told us another way he tried growing potatoes was in 3 or 4 old
tires. You lay one tire down fill with soil and seed potatoes, let them sprout up well,
then add another tire and more soil, careful not to cover the sprout tops, another tire, soil....
Found this illustration......
http://www.kiddiegardens.com/growing..._in_tires.html
and this one.......
http://www.youtube.com/watch?v=7FYoPOpAhwQ