Yeah, my test this year to see if all the buzz on the Internet about growing potatoes up and harvesting the full length of the container was true had similar results. The plants clearly didn't grow roots along the whole stem even after having dirt built up. Yes, the plant grows up and it is fine, but it still grows the normal amount of potatoes. A normal harvest is 5 to 10 potatoes per plant.
My plan for next year is to use rich composted dirt, no hay or layers at all, and only add dirt once to build them up a little, but then let grow.
