Hybrid begonias are generally outdoor plants and can withstand a small amount of coolness. When winter comes and the temperatures start to drop, the plants typically require a bit of extra care. The kind of care you need to provide depends on your type of hybrid. Some hybrids bloom in the winter, whereas others die and have tubers that need to be stored. Providing your hybrid begonia with a bit of TLC will help it to live through many winters.
Water your soil so that it is barely moist, but not completely dry, when it starts to become cold. Begonias typically become dormant in the winter and a sign of the dormancy is the death of the blooms.
Bring your begonia inside, if it is a hybrid that can survive indoors. Keep the plant away from light. In about six to eight weeks, the foliage will begin to die. When it does, cut the dead foliage off, leaving the stems about 3 inches long. Place the plant back outside when the threat of frost is gone.
Dig the begonias out of the ground when their foliage starts to turn yellow, if the plant cannot be brought inside. Cut the stems to about 5 inches long. Keep the tubers inside, out of direct sunlight to allow them to dry. Pull the stems off of the tubers once they are dry and keep the tubers in a plastic bag that is filled with peat moss or perlite. Keep the bag in a cool and dark place, such as a refrigerator set between 40 and 50 degrees Fahrenheit. Plant the tubers back in the ground according to your specific hybrid’s sowing time.