Common Mountain Mint (Pycnanthemum virginianum) is a seasonal plant with white flowers from summer into early fall. They prefer mesic soil in sun to part sun where they grow up to 3 feet tall. They are a good choice for slopes. Companion plants include Foxglove Beardtongue (Pycnanthemum virginianum) and Little Bluestem (Schizachyrium scoparium).
No serious maintenance needs.