Tuberous begonia choices recommended by Nancy Szerlag in her Annuals For Michigan by Lone Pine Press.
B. x tuberhybrida (tuberous begonias) are generally sold as tubers. The flowers come in many shades of red, pink, yellow, orange or white. They can also be picotee, with the margins of the petals colored differently from the main petal. The plants are 8–24" tall and wide.
‘Non-stop’ series begonias can be started from seed. They grow about 12" tall with an equal spread; their double and semi-double flowers come in pink, yellow, orange, red and white.
B. x t. pendula ‘Chanson’ are attractive pendulous begonias and have flowers in many bright shades.
Standard upright, multiflora types of tuberous begonias grow 8 to 10 inches tall and yield more, but smaller flowers. Flowers in the picotee lace strain have contrasting color on the edges of their petals plus scalloped edges.
Pendant types ‘Nectarine Rose’, ‘Fragrant Lemon’ and ‘Fragrant Apricot’ are ideal for hanging baskets and are fragrant.
`Madame Helene Harms' is a long-time favorite multiflora type in yellow. `Sensation' is a pink begonia, well suited for hanging baskets.