Joe Pye Weed (Eutrochium maculatum)
2 year plants in 4" pots.
Joe Pye Weed grows up to 6' in ideal conditions, but strong stems support the flowering plant so it rarely needs to be staked. The dusty rose-colored flowers will bloom for many weeks in July and August, becoming absolute magnets for dozens of species of butterflies. It will spread so should be planted with caution in small landscape situations.
(Image from Wikipedia)