‘Eco Bluebird’ Dwarf Crested Iris produces its showy lavender-blue flowers in April and May. They are displayed above the ground-hugging fans of light green blade-like leaves. Iris cristata ‘Eco Bluebird’ is very showy in spring, and less so as summer progresses because the foliage is ephemeral. The rhizomatous habit makes this delicate looking native a good seasonal groundcover for woodland settings and shady rock gardens.