Hi, I have a few crape myrtles that I'm trying to have grow into a tree shape with 5 or 6 trunks. I apologize for talking about both in the same post, but I have similar questions for either. One is a dynamite that's about 4 feet tall that's very healthy but only added about 6 inches this summer. The other is a Natchez. The Natchez's oldest branch/trunk didn't make it through winter, so I'm hesitant about cutting back any growth this year, but it's growing in every direction but up. You'd never know these two plants are related at all. The dynamite is compact and growing roughly up with wood that's hardening off. In the meantime, the Natchez is growing incredibly fast, but it's all green wood and drooping all over the place. The Natchez looks very healthy but has a bad sense of direction. In short, what is the normal way of training young crape myrtles to grown into trees?

Is it okay to tie them up (loosely, of course) to train them or is it better to just keep trimming them until new suckers start growing in the right direction? I can see training the dynamite as being helpful since it does seem to be hardening off, but the Natchez is almost all green wood, hardly, if any, branching, and 90% just leaves. Unfortunately, I feel I need to do something with the Natchez just because it's spreading outward and everywhere. The final question would be, how much distance should there be between the trunks at the base? Both trees' trunks are only about 2-3 inches apart. If I want it to eventually have 5 or 6 trunks, should I be allowing the outside suckers to grow so I can eventually have those outside suckers be the main trunks whereby there's more spacing?

Thanks for your help!