For things that bloom with the daylilies, I really like the self sowing flowers like coneflower, balloon flower, Sweet William dianthus, cornflowers, and petunias to fill in the spots between my shrubs and daylilies.
There are so many things for year round interest. I believe the soil you describe is similar to mine. Wish I had pictures handy, but I'm not at home right now. Here are some of my spring and fall flowers to fill out the seasons:
One of my favorite shrubs is the blue mist spirea that is just now beginning to bloom as the daylilies are winding down. The butterflies and bees love it.
I also love crepe myrtles and summersweet because they are blooming now. We sat outside yesterday and watched all the bees on the summersweet.
Two summers ago, I bought casa blanca lilies. They are in full bloom now and are a big hit with everyone who sees them. And you can be twenty feet away and smell them with a slight breeze coming at you.
I always get a little sad when the daylilies get down to the last ones, so these late blooming flowers help brighten up the mood.
