I don't think I ever experimented with begonias out front. I keep them in the back planters where they get a lot of sun and I didn't think they'd do well with zero sun. I think the red-leaved begonias will lose their color, but the green ones might work out. I'll give them a try this summer in one of the test planters, even a red-leaved variety just to see how they do and if they flower until fall.
