On Top® Sun Glow Tuberous Begonia

On Top® Sun Glow is a compact, mounded tuberous begonia with golden-yellow flowers edged in rich red. PanAmerican Seed lists the On Top® Series F1 at 10–12 inches high and wide; the exact Sun Glow selection has been reported flowering from spring through autumn. ## Flowers and form [NC State Extension identifies PAS1384156 as On Top® Sun Glow](https://plants.ces.ncsu.edu/plants/begonia-tuberous-types/) and describes its double, yellow-and-red bicolor flowers. The [Royal Horticultural Society’s 2025 trial report](https://www.rhs.org.uk/plants/trials-awards/using-award-winning-plants/fleuroselect-begonias-peoples-choice-winners) describes golden-yellow blooms with a rich-red picotee edge from spring to autumn and notes its suitability for containers and shady corners. The breeder’s On Top catalog lists a mounded habit and 2–5-inch series flowers. ## Siting Give tuberous begonias partial or dappled shade and organically rich soil that stays moist while draining freely. They do not tolerate drought, and saturated soil can rot the tuber. On Top plants are selected for greater heat and sunlight tolerance than many begonias, though shelter from harsh sun and wind can help in exposed gardens. ## Seasonal growing In cold-winter climates, bring containers to a frost-free place or lift and store tubers dry before frost. Start them indoors in late winter for planting out after the last frost. ## Maintenance Check pots regularly, remove spent flowers and damaged leaves, and maintain good airflow. Taper watering as foliage yellows in autumn. See [NC State Extension’s growing guidance](https://plants.ces.ncsu.edu/plants/begonia-tuberous-types/).