If they are maincrop spuds then they may not flower for a few weeks yet, but whenever it happens try not to dig them up until the tops start to wither and die down.
For reliability and quality, carol, you need to plant proper seed potatoes. You can never be sure what you will end up with if you plant just any old potatoes that happen to be sprouting. A friend of mine once planted a few left over potatoes he got from Tesco. Two didn’t do anything, and the other three produced carrots, with a rogue suede in amongst one crop. That would not have been too bad, except my friend doesn’t like carrots.
Had some of ours already and they never disappoint…no flavour like home grown can match shop bought ones…some are turning yellow so will dig them up tomorrow and see what is occuring…Have grown them in potato sacks and was pretty successful, but with so much space in this garden, in the ground for us…
carrots not much luck with them…or parsnips… Tomatoes though are easy just about anywhere…can make your own Tomato sauces and freeze them with the surplus…bolognese and lasagna need a good tasty sauce…
Maybe have a go at Tomatoes Carol, if you like them…you can get some instructions if you fancy growing them next spring…Your potatoes in the tubs look big enough, but sure your let us all know…