"CAGE METHOD ALTERNATIVE: Grow potatoes in vertical boxes, cribs, barrels or wire cages. Set your cage on prepared soil. Plant strong seed pieces 6" – 8" apart and cover lightly with 4" of soil. When the plant emerges and grows, begin adding mellow compost, mulch or soil always leaving at lest 6 inches of plant exposed. Continue this process until the plants stop their upward progress and/or blossom. Then let them finish out their growing season providing them with plenty of water. As the plant stems lengthen, so do the length and number of underground stolons, which are what produce the potato tubers. More potatoes form in less space and the yield is increased 2 or 3 times. This is a great way to grow a lot of potatoes with limited garden space."
Whether you can do this year-round, I do not know. I have fashioned a potato-growing device from a few stakes and chicken wire (an impromptu "pen") and from an old compost bin (like a metal box with holes in it) and even from a garbage can that was past its prime and to which I added a few more holes.