I LOVE phlox. I planted several way too late last yr and they didn't make it. I'm gradually finding replacements. I have a 4 ft tall pink phlox that the swallowtail butterflies adore. It starts blooming in late June for me and keeps going until I get tired of it in Sept/ Oct. It's also fragrant.
Arlene, your Franz Schubert, are the individual blooms as large as they seem? I had wondered about that one.
I have ordered 5 new plants from Perennial Pleasures in VT. They specialize in phlox.