I think I read that the tubers should get an anti-fungal treatment when they are dug up. The ones you planted may have not had the right treatment or storage before you got them, just a guess.
Cut flowers is the plan. I am hoping the dinner plate and cactus varieties will prosper in a high tunnel environment. The comments to some of the Eden Brothers pages mention them replacing non-sprouting tubers for their customers. I will see how it goes. My high tunnel dirt is ridiculously dry. I am going to go hose it down tomorrow to try to get some moisture into the soil. I know too wet is bad, but it's like the surface of the moon in there.
I also picked up a quarter pound of this sunflower mix, looked like a good deal:
https://www.edenbrothers.com/store/s...uty_seeds.html