Yes they are. All the Myrtles sold in local nurseries are hardy in this area. The more sun the better. They are used by VDOT and MDOT for median plants. As for vareties, your choice.

Especially any of the National Arboretum developed varieties are hardy here. They all have native American tribal names like Cherokee, Tuscarora etc. They don't die back in DC winters. They come in all sizes and colors.

Thanks, everybody. I was leaning towards Tuscarora, so that's good to hear.

I have to laugh (with loving kindness) about someone asking if CMs are hardy here.
Almost every other tree is a CM in this area! They come in so many colors you might not know it, but you probably have a ton in your own neighborhood.

A word of caution, althogh Tuscarora don't pretend to be any other color than they are. All the Arboretum reds heavily lean towards pink. Even their purples.

If you're looking for true-er colors, look towards the Whiteny Series.

Love them!
Christine

I'm laughing with you. Since the time I originally posted this question, CMs have flowered and I have indeed realized how common these trees are. I didn't recognize them without their flowers. They are EVERYWHERE! They are so pretty.

FWIW, the "wild type" Lagerstroemia indica, popular in the South for roughly 200 years, is definitely not hardy enough *to become a tree* in the colder parts of the NoVA (Fairfax and Loudoun counties) suburbs. I remember as a teenager growing up in that area, around the early 90s, they were much less commonly seen. The only true tree sized plant I can remember was in downtown Leesburg. The one in my parents garden near the Ffx/Lnd border would die back in about 1/2 to 1/3rd of winters. It would still manage to bloom that year from new wood, but that sort of thing could cause someone to throw the plant out for dead. So the OP might have once heard from an old-timer that crape myrtles were not hardy in the area. Around this time though, the National Arboretum hybrids involving L. fauriei started becoming popular. These can remain arborescent at temperatures around 0F, as well as having an improve range of colors.

I was recently in SE Virginia, though, and their popularity there far exceeds even in the Washington, DC area. It seems like over 1/2 of the planted trees are crape myrtles!