Garden phlox fills the midsummer border with large, domed clusters of fragrant flowers in pink, red, white, lavender and bicolours on stems 3 to 4 feet tall, from midsummer into early fall. The scent, sweet and slightly spicy, carries on the evening air, and it is one of the most rewarding cut flowers of high summer. It is a native of the eastern United States, from the Northeast to Georgia and west to Kansas.
Plant it 18 to 24 inches apart in rich, moist soil that drains, in full sun or light shade, and keep it watered; it is not a drought plant. It spreads steadily and responds to division every two or three years in spring. Thin the clump to five or six strong stems in spring for bigger flower heads and better air movement, and deadhead for a smaller second flush.
Powdery mildew is the main challenge. Choose resistant cultivars ('David', 'Jeana', the Flame series), space the plants generously, water at the base, and site them where air moves. Cut for the vase when about a quarter of the flowers in the cluster are open; the rest open over five to seven days. Butterflies, hummingbird moths and hummingbirds work the flowers; 'Jeana' is the best of all for butterflies. Deer and rabbits will graze it.
Ecoregions:Northern ForestsEastern Temperate ForestsGreat Plains
Powdery mildew
White or grey powdery coating on leaves - usually starting on older growth in humid conditions or when nights cool.
Improve air circulation by thinning plants. Apply neem oil or potassium bicarbonate spray at first sign. Avoid overhead watering.