I haven't tried this yet but someone told me of a fellow that planted potatoes in soil in a car tire. As the plant grew taller he just kept adding another tire and more soil until he had a stack of 7 tires. The guy said his yield was about 75lbs. of spuds per stack of tires. This might be a good way to grow potatoes in a city or urban environment where land space is at a premium, it would also be a pretty descreet way to grow too!! Just an ol' stack tires over there with some green plant pokin' out the top!! Little would the average looter know it would be packed with potatoes top to bottom! See ya later alligator!!