Garden Phlox -Every flower border should contain a generous helping of garden phlox. These big bloomers can grow 3 to 5 feet tall producing ball-like flower heads from mid-summer to fall. The fragrant flowers include pink, red, purple, white, or bicolor, and some also offer variegated foliage. In humid climates, look for mildew-resistant varieties. Garden phlox make excellent companions for roses, coneflower, and lilies. Grows in Zones 4-8.