I planted a crape Myrtle in a little neglected side yard 3 years ago. I really want to shape it into a single trunk tree (just a personal preference). I remember reading at the time of planting that you should leave it alone for 3 years before beginning to prune it for the trunk shape.

Anyone have a suggestion as to where/how to start this process for this tree? Or is it not even appropriate for this tree at this point?

Hoping for something like this in the end…

Spitballing here, not an arborist.

First thing I would check is the variety of Crepe Myrtle you planted and its growth habit to make sure what you want and what it will naturally want to do are compatible.

You could cut it back to 6 inches above soil level. If it doesn't die it will sprout new trunks. Since they will be competing with each other for light, they should grow much straighter, and when you get them to the height you want before it starts branching out, cut off all but the biggest one.

Or, trim all but one now and realize you're going to have a twisted bottom of the trunk.

Again, not an arborist.

Yeah I didn't really consider that this might be variety-dependent. Oh well I'm gonna continue to research it and if I don't get any solid info I'm just gonna wing it. Will probably wind up with a pretty crooked tree but it's gonna be a single trunk, by God!

Bet your desired look example is grown on a grafted rootstock.

I didn't because I'm AgNoResearch.

Good luck in your endeavor!

Thank you!

On a somewhat related question, I have been a bit perplexed by a CM I planted a few years ago. It seems as if it really hasn't grown much; I have given it moderate attention to this point with somewhat regular fertilizer and root stimulant. It looks fine, but just has not taken on much size, which is one of the main reasons I got it.

I think that will work just fine.

I hope so. Wont be pretty and straight like the ones I've seen online but like someone else posted that is probably grafted. I know these are pretty durable trees so I don't think this will harm it.

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Also a recent how-to was heard on radio https://kamu.tamu.edu/radio/radio-programs/garden-success/

Both have emails and may also have links to how-tos

I love CMs. They are Texas heat warriors and sadly all too often completely mismanaged. If a single trunk is what you want, I'd lay down a few extra $'s at the local nursery for something already trained vs buying from big box and attempting to manipulate it.

Unfortunately I didn't do enough research ahead of time and just thought this was an option for pruning any crape Myrtle. I agree that your advice is best but this is already done. Time will tell if it comes out ok or is a disaster.