I probably shouldn’t admit this, but I garden without paying much attention to where plants are supposed to grow. I’ll try most flowers once, and if they don’t like the spot, I don’t usually try again. With some notable exceptions (bloodroot keeps breaking my heart), plants will grow in my yard, whether in full sun in the front or in part-shade to mostly-shade in the back.
With that said, and perhaps not surprisingly, I’ve noticed that most of the summer prairie flowers in my yard bloom earlier and more vigorously in full sun.
All comparison photos were taken on July 24; sun first, then shade.
Bee balm was the plant that made me think of comparing the locations:


Yellow coneflower:


Joe-pye weed, just opening up in both spots, but a little further ahead in the full sun:


Pearly everlasting — all over in the front yard, but struggling to make it through all the creeping charlie in the backyard:


Dramatic difference for the black-eyed susan — a huge cluster in the front yard, but just one small plant in the backyard:


(Much more to come about the black-eyed susan situation in the front yard.)
Purple coneflower — not even a comparison because at that point, there were none in the backyard (and even today, August 8, there is just one).
I’m not ready to attribute all of the front-yard success to amount of sunlight alone. For example, in the case of the black-eyed susan, in previous years the results were reversed (few in the sun, many in the shade).
And even in part shade, the flowers usually do grow, just later, like the same backyard bee balm location, taken on August 7:
Aha! Now I know what is wrong with my pearly everlasting. I need to move it to more sun. This is a great post!