Our first batch of potatoes was sown in compost bags and yesterday, we harvested the first bag. Now, I haven't fed or topped them up as much as I should but even so, we got 2lb 12oz:
I didn't realise they would be ready but the bag next to it, when watered, showed some potatoes sitting on its surface. The variety is Winston and we were a bit worried as they are supposed to be watery but we found them lovely.
Two more bags to go plus 4 large tubs - should be interesting!