a pic will sure help set the scene ... ken

For whatever reason(s) they are growing like weeds on your site and making weak floppy growth that falls open and snaps off abnormally. Maybe something like too much watering, fertilizer or shade. If you can figure out what condition is present there that is "pushing" them and reduce or eliminate that factor that will probably be the best approach.

Otherwise every time the original branches are cut back or there is breakage the smaller, even less structurally sound replacement branches will then go on to break themselves. Unless you instead manage the trees by cutting all of the side branches down to points low on the perhaps initially shortened main stems every winter, resulting in shorter, smaller and more vertical specimens that never have long, multi-year growths present that bend out and break off. Handled in this manner there will probably be little breakage but a tufted, sprouting and vertical appearance will also be the likely outcome.

There are critical times when the flowers are at their peak when crapes are vulnerable to breakage after rains. Happens sometimes to mine too.

But I agree with Embo that you might eliminate some of the lowest side branches that are hanging down the most. And then cut back by a few feet the longest ones that are being pulled down.

Of course, once it's done blooming, rain should not be a problem for a while.

i dont do CMs in MI ... but could heavily fertd lawn.. be a problem???

i cant tell if the lawn is fertd on this pic ... but i usually note these in foundation plantings or beds .. rather than in tree form in the lawn ...

ken

Actually I was talking about cutting the whole thing down to shorter main stems next winter and then pruning all secondary shoots down to short lengths each winter after that. Allowing each one to grow a little longer each time. Instead of a lot longer. As long as the resulting appearance was to your taste that would be a way to prevent future breakage due to the newest branches not being so long and bent over.

They say when you cut a branch it will come back as 2.

I would like a strong trunk so as to look more like a tree.

There are 3 main trunks, at around 5 feet they have some 2" - 3" branching out. Should I cut the 2-3 inch ones back even with the mains ?

"They say when you cut a branch it will come back as 2."

it's just not that simple- it depends on where and how exactly you place your cuts. Read up on it before you start- you could ruin these and make it worse or you could enhance them and make them stronger. It all depends on the skill and knowledge of the person doing the pruning.

If I cut the lower one on the left and right, the umbrella effect will be tilted to the right. Notice how there are a number of 2" plus branches to the right. If I cut them close to the trunk, will new ones grow back.

Will the top take care of itself.

I assume that you can prune any time of year, winter is always suggested because then everything is more visible.

Desire a tree effect.

With my Natchez, because of the usual winter die-back, the resultant vigorous base-sprouts are very long & eventually splay out. Solution -- trim them back early on & continue trimming if they still get too long.

This past winter was very mild & only alittle die-back, and the result this summer is much better growth -- alot of sprouts along existing stems & no sucker sprouts from the base.

Take the longest top branches back to their laterals, making proper height reduction cuts (this winter). Branches of crepe myrtles bend and break. It happens, and there isn't anything to be done about it. Whatever you do, DO NOT "top" the tree, cut it back to the bare trunks, etc. With height reduction cuts, the tree shouldn't look stubbed.