You can grow 100 pounds of potatoes in a 4 sq ft box with your own ‘potato high rise’. As the potatoes grow you simply add another layer. This particular method is nice in that the author creates interlocking corners in his potato box.
Yes, potatoes are inexpensive, which is why this is probably more for preppers and avid gardeners than anyone else.
To harvest from your box, first access the bottom layer by removing frame’s boards. When you have removed all of the potatoes from that level you replace the soil and reattach the boards. When you want to harvest more you repeat the same steps with the second layer and so on.