On Top® Polka Dot Tuberous Begonia

On Top® Polka Dot is a compact, mounded tuberous begonia with variable bicolored flowers: coral and red blooms with white spots, and white blooms edged in red. PanAmerican Seed lists the On Top® Series F1 at 10–12 inches high and wide. ## Flowers and form The breeder’s [2026–2027 On Top catalog](https://catalog.panamseed.com/view/445948364/36/) describes Polka Dot’s changing bicolor patterns and shows a series flower size of 2–5 inches. The rounded plants suit patio containers, window boxes and sheltered border fronts, where the changing flower patterns can be seen close up. ## Siting Tuberous begonias prefer partial or dappled shade and organically rich soil that stays moist but drains freely. Avoid drought stress, standing water and strong wind. The On Top series is promoted for greater heat and sunlight tolerance than many begonias, but partial shade is still a reliable place to start; containers help with shelter and drainage. ## Seasonal growing Tuberous begonias usually flower from early summer until frost. In cold-winter climates, bring pots into a frost-free place or lift and store the tubers dry before the first frost, then restart them in late winter. ## Maintenance Check containers regularly, remove faded flowers and damaged leaves, and keep air moving around foliage. Reduce watering as leaves yellow in autumn. See [NC State Extension’s tuberous begonia guidance](https://plants.ces.ncsu.edu/plants/begonia-tuberous-types/) for additional care details.