Annie they are my tubers that I have had for many years and just keep in the basement after digging and washing. I did check one and it had completely rotted. Haven't checked all the others, there are about 12 more that have done nothing so will take your advice and check them out this weekend.
Amazing that you had some come back. I just pot mine in pots and sink in the ground so I don't miss them when I dig them up in the fall.
