Marsh phlox, also known as Smooth Phlox, is a clump-forming perennial that typically grows 2-4′ tall. It naturally occurs in wet woods, wet thickets, wet meadows and low prairies. Aromatic, pink to reddish-purple, tubular flowers appear in large, cluster ... s atop stiff, upright stems. This plant seldom needs staking and is one of the few tall phloxes to bloom in spring. This species is very similar in appearance to Phlox paniculata (Garden Phlox) except it blooms earlier and leaves are hairless and narrow. Smooth phlox is a good cut flower.