There are many selections of Moss Phlox, all of them forming a low mound or cushion of dark green needle-like leaves, throughout the spring and summer months the evergreen cushions are drenched with tiny White flowers. this beautiful perennial is often used for flower borders, rockeries, for edging, or in mixed containers.. this evergreen perennial grows best in well-drained, fertile soil. Good drainage is paramount when growing Phlox. drought tolerant, once established