Heavy clay soil here coupled with warm wet winters. I'm afraid of rot if left in the ground. Warmth in the green house was probably the problem. Then I had some flooding in my basement in December which put a lot of humidity in the air. My tubers were in plastic bins and they sweated which is why I changed their packing and I put them in cardboard boxes. I've also had a dehumidifier running ever since. But then I worried all winter the mice would find them, but they didn't. Maybe having 7 cats prowling about helped! So much to think about. Yesterday I started planting all my tubers up for an early start. This is the first time I've done that. It'll be another month before the last frost. My new dahlias are starting to arrive. 72 new ones! I'm getting so excited.