While I’ve been away the potato plants have grown significantly. So in attempt to expand the productivity I decided to experiment with the tower concept.
Effectively, I wrapped the existing pots in fencing wire and then lay straw around the edges. Thus created a cavity inside which I then filled with soil.
Apparently potatoes only germinate above the point where the seed was positioned (which if you think about it makes total sense). And so, one can increase productivity by increasing the amount of soil above that point.
Much easier and effective to do with the tires, so I’ll look to expand that method next time.