Hmm. New England Aster is in my Wildflower book. It does seems that butterflies tend to come more in the fall, so getting something like an Aster is a good idea. Maybe I should swap out the Prairie Blazingstar and swap in an Aster.
From the wildflower farms website:
Smooth Aster is one of the most attractive and long-lived of all the asters. Blooming from late August through to the end of October, it puts on a fabulous floral display producing clusters of dainty blue flowers long after most flowers are finished. A favourite stopping spot for butterflies, this Symphyotrichum laeve (formerly called Aster laeve) does well in just about any well-drained soil.
So, my new list would be this:
1) Asclepias tuberosa - Butterflyweed - orange
2) Coreopsis lanceolata - Lanceleaf Coreopsis - yellow
3) Panorama Mix Bee Balm Seeds - pink, white, purple,red
4) Symphyotrichum laeve - Smooth Aster - Lavender/Blue
I think this is looking really good. Thanks for all of the feedback!