What Are the Moisture Requirements for Phlox paniculata 'Iris'?
Moist but well drained

Phlox paniculata 'Iris' · Phlox paniculata 'Iris'
Thrives in any fertile, humus rich, moist soil in full sun or part shade. Plants will benefit from good air circulation and from watering in extended dry spells. Water at the base if necessary, rather than over the leaves
Moist but well drained