Red begonias in bloom.
image by Patrycja Cieszkowska/sxc.hu
Begonias are available in many colors and varieties, including single and double flowers as well as a range of petal shapes. They grow in clumps from tubers. While they flower for most of summer and into autumn, begonias do not fare well in cold winters and must be properly stored before the ground freezes completely in the fall. In the spring, replant the begonias in the garden so they can begin production for their new summer display.
Reduce watering to once a week in late autumn to force begonias into dormancy. Cease fertilizing at this time and allow the foliage to die back naturally.
Dig up the begonias as the foliage begins to die back or after the first frost, whichever occurs first. Dig around the tubers in a circle to avoid cutting them, then lift them out of the loosened soil.
Cut the stems down to five inches with a sharp knife or garden shears. Lay the tubers on a layer of newspaper in a dry room away from direct sun for five to seven days.
Fill a perforated plastic bag with dry peat moss or vermiculite. Place the tubers inside without touching one another.
Place the bags in a cool, dark place with a temperature between 40 and 50 degrees Fahrenheit. Check the tubers every two weeks during storage for soft spots or other signs of rot, and discard any that are affected.