They are a Southern "thang" and dicey when you get below zone 6 as far as I know. If you have the right micro-climate in your yard, could be???
If you can grow them, they are definitely worth a try. They bloom in harsh conditions of full Summer heat and drought ... and at a time when little else is in full bloom. Plus they smell very nice. One of my faves. That one in my the picture actually looked even better before it was tossed about by the strong winds of a thunderstorm.
According to my
Southern Living Garden Book, Lagerstoemia fauriei, the Japanese Crepe Myrtle, is hardier than L. indica, the Southern Crepe Myrtle ... but I believe it only blooms white. Still might be worth checking into it.