We have something here in NC we call the 'RedNeck' tater growing method. But instead of a box which costs lots of money and would require someone to actually build something, they use old tires. First you open up a little soil in you garden and lay down an old tire (tar down here in NC). Then you just lay in four or five nice tater seeds, eye side up. Cover the seeds with about 4 inches of good garden soil. You'll want to powder your seeds with ag surphur before planting them. When the tops come out and get about 4 inches high, completely cover 'em up with dirt. In a day or so the plants will recover an start pushing out again. What happens is that the tater will then send out offshoots at that level. Add another tire and repeat the process 2, maybe 3 times. I've heard 4 or five times will work. Then when you want some taters all you have to do is dig out the ones in the topmost tire. Then you remove the top tire and lay it on the ground next to the stack you took it from. The ground should be broken up under it too. Add some tater seeds to the bottom and then use the dirt from the original stack to cover them up with. You can keep this going all spring, summer, and fall. I know folks who are eating redneck taters from their tire garden up into December.
