Phlox stolonifera (Creeping Phlox)
Creeping phlox is a very hardy and attractive groundcover to use under large shade trees, I use it under Acer platanoides (Norway Maple). It is very showy when in bloom, particularly when planted in masses. Clusters of blue flowers carpet the ground in early May with a height of 10 to 12 inches (25-30 cm). It ranges from Quebec south to Georgia and Alabama.
It spreads by rhizomes and will fill a large area in humus-rich, slightly acidic to neutral soil, in partial shade to full shade with moist to average conditions. But, I have sandy soil and it is doing just fine. Divide the clumps in spring or fall.
Creeping phlox looks fantastic with Foamflower (Tiarella cordifolia) and Christmas Fern (Polystchum acrostichoides).