As their name implies, tuberous begonias sprout from underground tubers that function much like flower bulbs. Every winter, the begonias need to be dug out and stored until the weather warms up the following spring. Provide your begonias with the storing environment they need to survive so they can continue contributing lush growth and brilliant blossoms to your flower beds.
Dig the begonias out of the ground with a shovel before the last frost date in your region, according to Clemson University. If you're not sure when this is, consult your regional cooperative extension office or the Farmers' Almanac.
Trim back the leaves and stems of the tubers to a height of a couple of inches using pruning shears, suggests Clemson University. Leaving the foliage on the begonia tubers will cause them to dehydrate quickly.
Spread the begonia tubers on sheets of newspaper in a cool and dry indoor room. Let them dry at room temeprature for four or five days, recommends the American Begonia Society.
Slide each begonia tuber into its own paper bag and place the bags in a cardboard box. Store the box in a cool, dark place with a temperature between 45 degrees and 55 degrees Fahrenheit, according to Clemson University.