I know that some database entries say not suitable for containers and I totally agree with that for the ones that grow to monster sizes but I've grown Crepe Myrtle (Lagerstroemia 'Ebony Flame') in a container for two full years now and it hasn't skipped a beat; currently in full, glorious bloom. The Black Diamond series of Crepes are said to grow 10 to 12 feet I think but they can always be kept pruned to a desired size. Here's a list of the Black Diamond Crepe's: http://garden.org/plants/searc...
~ I'm an old gal who still loves playing in the dirt!
~ Playing in the dirt is my therapy ... and I'm in therapy a lot!