Moss Phlox blooms light up the ground layer just when our Redbuds and Dogwoods are in bloom. They are a valuable source of early-season nectar and are available in a variety of colors. 'Amazing Grace' blooms white with a pink center, blooming  in late March (in NC), continuing 5-6 weeks.
 
Moss Phlox does well in full sun in well-drained soil and is moderately drought tolerant. It is deer resistant (my deer, at least), though rabbits may find it enjoyable. 
 
These densely blooming, low-growing, evergreen ground covers attract butterflies, hummingbirds, skippers, and bees.