Years ago, I paid my local nursery a high price for a Crepe Myrtle growing in a hanging basket. I was told that it was double the price of the other Lagerstroemias because it was "specially bred" to stay small. The plant took no notice of this foolishness, of course, and I soon acceded to the plant's clearly expressed wishes and planted it in the ground. It's now taller than my house.
The best thing about Crepe Myrtles is the lack of special care they require. Most of the trees on Main Street in my town are Crepe Myrtles, and they're also planted along some of the freeways in Northern California because they grow and bloom without any need for landscaping maintenance expenses.
