The amsonia hubrechii and the Itea virginia Sweetspire. There are some really hardy mums that can be planted. Forget all the bright colors. The yellow cripps false cypress with winterthur viburnum Clean your bird baths ready for the winter months. Caryopteris has been doing very well for us.
Monkshood has some late flowering ones.
The deer won't eat them either. One of the great delights of mid summer are the magnificent new Rose of Sharons. This pure white form is a gem. It's called pink Chiffon. The good old fashioned Bluebird variety.