Answer: Crepe myrtles are best propagated by softwood cuttings. The following web sites are excellent guides for the details of how to do this. They will provide much more detail than we can in this short space:
You can also grow crepe myrtles from seeds. Sow the seeds indoors on the surface of a good seed starting mix. Don't cover them up. Keep them moist and they should be up in two or three weeks.
Q&A Library Searching Tips