Hi bupster, :D
Mine survived well all winter , covered in fleece, I have just dug up the last one :'( Only one of mine failed to make it , it just went rotten from the bottom.
I would have thought that they need digging & eating pretty quickly, & if you haven`t sown this years crop , do it soon. You could also order from Dobies, pre grown plants that will be delivered at the end of May. This is much simpler than growing them from seed. £3.95p for 20 plants. seems pretty cheap to me .
Adrian.