Behind it I planted curly kale. It's a very tough winter vegetable, but sow the seed in spring and it’s a dual-purpose summer foliage plant—after all, you can still pick a few leaves for the kitchen. Its blue-green crinkled leaves contrast well with the glossy fresh green begonia leaves and make a lovely background for the flowers.
Taller and farther back I planted Pineapple Queen coleus. The bright yellow foliage—with reddish marks at the base of each leaf, red veins, and (sometimes) red edges to the lobed leaves—contrasts in color with the kale yet harmonizes with the begonia flowers.
Take cuttings of the begonia and coleus for overwintering frost free—and when the frost has killed them, eat the kale!