Experts and BHG readers answer.
Thanks for writing. Dig the tubers after your area's first frost, then let them dry in a warm spot for a couple of days. Knock off excess soil and once the tubers seem fully dry on the outside, pack them up in dry sand or peat moss for the winter. Check on them a few times before spring, then plant them back outdoors after the soil has warmed.
---Justin, Senior Garden Editor, BHG.com