Crepe myrtle is easy to propagate by cuttings. This is how I did it. From Auburn University:
crape myrtle can be propagated easily through several methods. The most commonly used methods of propagation are hardwood and softwood cuttings. To propagate by hardwood cuttings take 8 inch long and 1/2 inch diameter cuttings in early to mid-November. Stick several cuttings in a container filled with a potting soil or well drained garden soil. About an inch of the cutting should protrude above the soil line. These cuttings can be left outside but should be protected from severe freeze. Once new growth emerges place the container in a sunny location and keep watered until you can plant them in the summer or fall.
Softwood cuttings consist of 4 to 6 inch cuttings taken from actively growing shoots at any time during the growing season. The cut ends can be dipped in a rooting hormone and then stuck in a well drained potting mix. Keep the cuttings misted to avoid drying out before roots can form. Rooted cuttings can then be planted in larger pots and grown to a larger size to improve survivability when placed in the landscape.
At 1 am this morning, it was 40 degrees, so it didn’t freeze here last night. Right now, at 10:20 am, it is 39.
There is a lot of difference in temp. between Fort Worth/Dallas and here.