All of these plants should be dug after frost has at least partially browned the foliage. Then, allow them to dry for about a week in a shady, well-ventilated site such as a garage or tool shed. Freezing temperatures should be avoided. Remove any excess soil and pack them in peat moss, vermiculite, or perlite. Make sure the bulbs don’t touch so that if one decays, the rot doesn’t spread. Dusting them with fungicide before storage will help prevent them from rotting.
Caladium should be stored between 50 and 60 degrees F. The other bulbs mentioned should be stored as near 40 degrees F as possible. Finding a good spot to store the bulbs may be difficult. Some people place them against a basement wall farthest from the furnace and insulate them so the wall keeps them cool. (Ward Upham)