No it's not too late to prune, but cut the smaller side branches as well. CM is one of those plants that always develop new branches so keep them pruned as well.

Here is a link that might be useful: Propagating Perennials

Well, I would disagree with Bullthistle on this. It's usually better NOT to do a general trim of the ends of the branches of ANY shrub - it used to be seen as "a good thing" but newer studies have shown that it is rarely needed. While not as drastic as some you have seen, you have effectively altered the natural shape of your crape myrtle. If you are growing a hedge, that's one thing, but this is a crape Myrtle, so I would say let it grow naturally. Take off any dead or spindly looking branches and any crossing branches, and any that are growing toward an unwanted spot or direction. Since you have done it, you may need to go back over the growing season and take off any wrongly growing branches or thin out the mess if you get lots of growth from the cut ends. Next year, resist any temptation to "tidy up" the CM, unless you are taking out the shoots from the base. If the CM is too big for the area it is planted in, dig it up, move it to where it HAS room, and plant a smaller cultivar, or other shrub/tree in its place.

If you want to shape it a bit, then follow the accepted "good pruning practices" - take branches off only if the tree is clearly better for it - take them off back to the trunk, to a larger-diameter branch, or to an outward (or whatever direction you want the new growth to go) facing bud. Don't take off more than one quarter to one third of the total branches at any one time. And last but not least - look carefully from all sides of the tree/shrub before cutting a branch off - you can always come back later and cut, but you can't re-attach a branch once it is off.

I agree with dibbit.

I will never understand why people chop on trees and shrubs without understanding what it's doing to the plant. My mom perfomed "crepe murder" on her crepe myrtles early last year. They were so beautiful before she pruned them. Now they just look aweful!

The crepe myrtle is one of the most commonly planted landscape trees in my area. Often, they're planted directly below power lines....which amazes me, since there are plenty of mature crepe myrtles in the area to exemplify the size they can achieve.

Anyhow, many homeowners prune their myrtles into dense "orbs." This seems to create very dense flowering, but I'd assume that it doesn't allow much light or air circulation inside the tree's canopy.

Others prune their myrtles into a trunk with naked "clubs" at the top - as many do with sycamore and mulberry trees. I've heard it makes for a weaker tree, with weaker branch connections.

Josh

Here's a thread from the Texas Forum.

Here is a link that might be useful: Crepe Murder