Thanks Phil and Chuck. I'm going to cover this plant for a while in hopes we have a long, warm fall so it can start to harden. We are expecting near freezing weather this weekend. I will probably use a blanket to cover it before it gets dark in hopes of trapping some heat from the ground. It's hard to tell from the picture, but this plant is nearly 5 foot tall and very bushy. I hope I have a blanket large enough. Except for a couple of known hardy varieties, I have been moving my potted plants to winter protection for the past 6 years. If I had this problem before, I don't remember, because they were not vulnerable like my plants are now in the ground. I'm just glad it is only one plant.
Mike in Hanover, VA