Begonia is a vast genus of flowers and tuberous begonias (Begonia tuberhybrida) grow from underground root structures called tubers, which need to be stored during their dormant stage. Grown in all climate zones, tuberous begonias are planted in the fall in U.S. Department of Agriculture plant hardiness zones 10 and 11. In cooler zones, plant them in spring or early summer when temperatures stay above 65 degrees Fahrenheit. With proper care and storage, you can enjoy tuberous begonias for years.
Water tuberous begonias once a week during dry weather during their growing season. Do not over-water by allowing the soil to become soggy.
Fertilize tuberous begonias during their growing season once every two weeks, with an all-purpose fertilizer, applying half the recommended dosage. If you use a liquid fertilizer, dilute with 1 part water. Apply fertilizer carefully and evenly around the begonias, avoiding the foliage.
Deadhead wilting flowers from tuberous begonias before they form seeds to improve their appearance and to prolong the flowering season.
Allow tuberous begonia foliage to die back naturally rather than cutting it back, once the plant is finished flowering. During that time, the foliage is still absorbing light to store in its tubers for next year. Expect fall-planted begonias to die back in late spring or summer, and spring- and summer-planted begonias to die back in fall.
Lift tuberous begonias from the ground with a garden fork when the foliage turns yellow and starts to fall off. The tubers should be just below soil level. After lifting, cut the foliage at the soil line, not right at the tubers, where you could cause damage.
Set the begonia tubers in a dry, cool area, such as basement or cool closet. Do not wash the soil off at this time. In two to three weeks, the tubers are ready to be stored until planting time.
Brush off the soil and cut off any remaining foliage and roots. Coat the tubers with a fungicide labeled to protect bulbs, applying it according to the manufacturer's instructions.
Store the bulbs in a paper bag or box filled with dry sand, vermiculite, peat or sawdust to prevent moisture loss, recommends Purdue University. Place the bag or box in an area with low humidity and temperatures between 45 and 60 F.
Things You Will Need
- Garden hose
- Pruning shears
- Bulb fungicide
- Paper bag or box
- Sand, vermiculite, peat or sawdust
- University of Florida IFAS Extension: Begonia Tuberhybrida: Hybrid Tuberous Begonia
- Purdue University Cooperative Extension Service: Winter Storage of Geranium, Canna, Gladiolus, Caladium, and Begonia
- Iowa State University Extension and Research: Growing Tuberous Begonias in the Home Garden
- University of California Statewide Integrated Pest Management Program: Begonia—Begonia spp.
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