For perligoniums (geraniums) you need to keep them cut back. Yes, they grow fast but if you let them get leggy, they'll look horrible. You can take the cuttings though, and just stick them back into the dirt, and they will root and grow! (Cuttings less than 6" are best.) One of my favorite... hey! I don't have any planted here!

What about begonias? They are bushy and colorful. I would think if they can handle Florida heat and sun, they'd do fine up there!