Phlox paniculata (S, F)
Hardy in Zones 3-8.
If roots appear dry it is helpful to soak them in warm water for a few hours to overnight before planting. They need full sun and organically enriched soil and benefit greatly from monthly fertilizing. Set the plants 12"-15" apart with growing tips 1" below soil surface. They will form sizable clumps which can be divided every 3 years.
Cut off spent flowers to extend the bloom time. Water during dry periods. Taller varieties may need staking. To prevent powdery mildew, provide good air circulation, keep plants healthy, and use wettable sulfur at the first sign of infection.