I am trying spuds in containers this year so I tried 15 different varieties as an experiment. I gave them plenty of space - 1 seed potato for every 5 gallon drum. I used a mix of compost, garden soil and rotted horse manure. Plants were fine. I left them in the ground for a month or so now after the plants have died back, but the yields are much smaller than i expected.
I'm getting 1-2 lb (500g-1Kg) for each seed spud. That's only half a dozen or so average size spuds. I was expecting a lot more. Previously I've planted them in rows and it's difficult to tell how much you've got.
Is this normal?