I was hoping you'd get a response from others who have done this because I'd like to get some ideas, too.
We have grown sweet potatoes in containers with good success. I've grown them in 3 gallon nursery cans of pure potting soil (peat moss, perlite, vermiculite) and they did very well and produced a nice crop.
Last year we grew them in a huge terra cotta pot on our back porch and they grew all over the place and made some really nice potatoes. We filled that one with 50/50 potting soil and compost.
