I bought this for the 2nd time from Plant Delights Nursery in June, 1997. I bought the first in June 1996. I tried leaving it outside over the winter. It was buried well and was mulched with masses of oak leaves. We had a 7b winter (usually zone 7a but this was warmer than usual). The bottom temperature was 5 degrees and that was just two nights, the rest of the year bottomed out at 10. Despite that, it turned to mush by spring. The tubers will spend this winter indoor. I had purchased just one tuber but there are already 2 offsets.