Garden Phlox (Phlox paniculata) is a seasonal plant with pink blooms in summer. They prefer moist to mesic soil in sun to part sun where they grow up to 4 feet tall. They are a good choice for slopes. Companion plants include Shenandoah' Switch Grass (Panicum virgatum 'Shenandoah') and Rough Blazing Star (Liatris aspera).
Powdery mildew and root rot are sometimes problematic. Cutting stems back in early June will promote a bushier habit. Tall flower stalks may need to be staked.