The Best Time to Transplant Begonias

Species

• The 900 species of begonias are all hybrids. The original genetic parents are extinct. While they flower in all regions of the United States during the summer months, the tubers are not winter hardy in temperate climates. Begonia tubers need a dormant, or rest period, between growing cycles. Overwinter them inside, at 40 to 50 degrees Fahrenheit, if you live in an area with freezing temperatures.

Best Time to Start the Tubers

• Start the tubers inside during February and March, as it takes approximately four months from planting to blossoming. If you plant the tubers during both months, you will enjoy blooms for a longer period. February plantings should bloom in June, and March plantings blossom during July.

Best Time to Transplant

• The best time to transplant begonias outside is after all danger of frost is past. Start hardening off the plants, both upright and cascading varieties, approximately two weeks before the last frost date. Then, provided your region does not have a late winter frost, you can transplant them directly into the garden bed. Alternately, with cascading varieties, you can transplant them to hanging planters.

Flower Size

• While the size of a tuber does reflect the size of the plant, it does not have any effect on blossom size, according to University of Minnesota Extension. Pinch off extra stems from the upright varieties to encourage larger blossoms. Many cascading begonias are specifically cultivated to have smaller flowers.