Thank you Mike and Al.
I know I'm adding this to the plants I'll be expanding at the farm. The bees love this plant. One site called it a perennial, so I going to mark the plants and if they sprout again in the spring, I'll be making some beds.
Seeds do seem to be available at several suppliers. This would be a great background plant for flower beds as it lasts all summer and flowers for a long time, growing several feet high.