A new cultivar of Phlox plant named, ‘Plumtastic’, that is characterized by its low dense groundcover habit, its petals that overlap for one-half to three-quarters of their length, its flowers that emerge light rose pink in color, ageing to a medium and then dark rose to red-violet color, its flowers that emerge with a large, distinct center eye that is white in color and fills with pigment as the flowers age, its small petal striae that form two distinct dark violet lines at the base of each petal lobe and persist for the life of the flower, and its flowers that cover 90% of the plant at peak bloom.
