Hey Jeffrey, have you grown seeds from this crApe myrtle and seen the resulting flowers? Chances are nearly 100% that most, if not all, of the resulting plants will not bloom red. The reason I'm pointing this out is because you said you had found a "red-flowering cr(a)pe myrtle seed source", which sounds to me like you are saying the seeds will result in red-flowering crApes. All of the commercially available crApe myrtles, that bloom red, are reproduced vegetatively. Of course, as with all seeds, there's a chance that a seedling may turn out to be something truly wonderful and the next great cultivar.