Potatoes flowering

[Containergardener]

My potato bags (planted with seed potatoes in 2016 ) , which produced more potatoes last yr.
I thought id finally cleared everything from the bags and dumped them at the side if the house.
They were buried under 3ft of snow and started growing again (no idea of variety, the names have come off).
This yr they are starting to flower though hadnt the past 2 years. Any idea why?

[Mr Bones]

Maybe they're flowering because of the warmer weather this year, mine always have a fine show of flowers.

[Containergardener]

Maybe they're flowering because of the warmer weather this year, mine always have a fine show of flowers.

Yes, i think that may be it. Unusually warm dry summer here for us.