there are CM's everywhere around Houston, they are very resilient, and withstand our heat, droughts, floods, and even severe pruning.

i've seen many that are topped at around 4-6' tall every fall and they keep growing back each year. i've seen some giant ones that are never or hardly ever pruned, like the large droopy umbrella shaped ones you mentioned.

mine were planted close to the house, so i only prune the ones that are within a few inches of the roof. and i also prune the suckers. we've been at this house for about 4 years, and they are about 15-18' tall, and have a nice spread with lots of blooms.

You are doing it right, Pattycakes! You won't get away with Crepe Murder on this forum. Don't chop off their heads!

The best time to trim crape myrtles is when your saws are sharp. (In other words any time). Thin, shape, trim, but never top them off.

Yeaaaaaaaaaaaa~~at least that's one thing i'm doing right!

Elchechex, what do you mean by 'thin'? ;o)

Some prune back or dead head after they bloom to promote more blooms. Some once they have gotten larger any branch that is smaller than a pencil but most of yours probably aren't any larger than that now. All Suckers that come up from the ground or you will end up with a bush. If those suckers are far enough away from the parent plant you might want to dig them up at is if you want more plants. If you have ever moved one you will see many suckers come up from the roots that get left and each and everyone of those will most likely do better than the one you moved.

Here's a great article (with pictures!) from the Houston Chronicle about how to prune a crepe myrtle:

Here is a link that might be useful: Guilty of crepe murder?