I recently split 2 LARGE groupings of Dutch Iris - one of the groupings didn't produce any blooms this year, so I was told that it was time to start splitting them. Let's just say it was a huge harvest! I gave tons of them away and replanted some immediately, but I am left with 3 gallon ice cream pails full. What is the best way to winter these Dutch Iris? I have no more space to plant in the ground, I do have some pots, but again planting in ground is probably not an option. I have vermiculite if that would be a proper way to store them? Right now they are in some moist dirt, but I know I need to do something with them ASAP... BTW- I live in Southern Wisconsin and temps are dipping into the low 50's at night.

Thanks in advance!