Largeleaf phlox (Phlox amplifolia) is a sun-tolerant plant that's resistant to powdery mildew, a fungal disease that affects many flowers. The native plant produces underground runners that slowly spread to form a large mass. "Blooming in early summer, the airy pink inflorescences are held 1 to 2 feet above the mass of foliage and continue to bloom for about six weeks," says Leirion Sorensen, the gardens manager at Mt. Cuba Center.

Zones: 3 to 8
Size: 44 inches tall x 36 inches wide
Growing conditions: full sun to part shade; loamy, well-drained soil