How do I overwinter tuberous begonias?

Question:

How do I overwinter tuberous begonias?

Answer:

Carefully dig up the tuberous begonias within a few days of a killing frost.  Leave a small amount of soil around each tuber.  Cut off the stems about 1 inch above the tubers.  Place the tubers in a cool, dry area to cure for 2 to 3 weeks.  After curing, shake off the remaining soil.  Place a layer of peat moss, vermiculite, or sawdust in a small cardboard box.  Lay the tubers on the storage medium, then cover the tubers with additional peat, vermiculite, or sawdust.  Store the tubers in an area with a temperature of 40 to 50 degrees Fahrenheit.  Do not allow the tubers to freeze.

More information can be found in this article: How to Overwinter Tender Perennials