Jane and Roger, thank you for your wisdom. I took out the tubers to investigate. Well, they looked just as intact as I received them. Not mushy or suspicious in any way. I soaked them overnight and I will put them in the refrigerator for a months. Perhaps that will give them a push. I received some stellata corms from Siberia last March and they didn't show either. But 2 out of three showed up about two weeks ago. I kept them under cover around °0C all winter. Gerhard