Creeping phlox is also known as "moss pink." As you can see from this picture of my rock garden, it is a very appropriate and descriptive name. Phlox makes for a striking burst of color in May.
A herbaceous perennial, phlox enjoys full sun and is evergreen once the flowers have stopped blooming. The only work phlox requires of me is an annual trim to keep it from "creeping" out of the bed.
Phlox comes in several different colors: variegated, purple, pink and white. Last year I added two clumps of variegated (white with pink stripes) to this rock garden. Judging from the "moss pink," they should do just fine in Zone 5.