For a flower garden that blooms all spring and summer, consider adding “companion plants” to your beds. These are plants that share a similar need for sun and well-drained soils, but many of them bloom at different times of the season than bearded irises. A few that do well are phlox, gaillardia, daylilies, pansies, and rudbeckia, which will bloom after the irises are finished. Early spring bulbs such as daffodils, anemonies, and hyacinth can provide color before the irises get going. Planting annuals such as zinnias and petunias can add bright color to the front of a bed. Experiment and have fun! For more ideas, visit the links below.
Here’s an excellent article from Schreiner’s Iris Gardens on companion plants.
This article from the American Iris Society offers some great ideas.
If you’re interested in smaller bearded irises, here’s a great YouTube video on planting them with companion plants.