Two perennials that are very hardy and love full sun are purple coneflower and heliopsis "summer sun". Both are grown very easily by seed and are very prolific at reseeding too.
A bonus is that in the fall when the seed dries out the goldfinches love them. They come to my yard by the dozen to pick the seeds and eat them.
A bonus is that in the fall when the seed dries out the goldfinches love them. They come to my yard by the dozen to pick the seeds and eat them.