- Dig up the tubers right after the first frost.
- Cut back any foliage to about 2 inches
- Carefully did up the clumps
- Remove the soil but do not wash and allow the tubers to dry for an hour.
- Place them in paper bags filled with dry peat moss, perlite or vermiculite.
- Store bags in a well-ventilated but cool place
- Check every few weeks for rotting, infested or dry roots and toss out
- For larger flowers do not divide root clumps.