Ironweed (Vernonia fasiculata) is a seasonal plant with purple blooms from late summer into fall. They prefer moist soil in full sun to part shade where they grow up to 4 feet tall. They are a good choice for sunny basins. Companion plants include Palm Sedge (Carex muskigemensis) and Ohio Spiderwort (Tradescantia ohiensis).
Plants may need staking while in bloom. To prevent self-seeding, remove seedheads in mid-fall.