Phlox subulata Cushion Blue

The Phlox subulata 'Emerald Cushion Blue', better known as Moss Phlox, is a small, spreading, evergreen perennial that disappears from late spring to early summer under a carpet of delicate blue flowers with a deeper blue-violet center. It grows rapidly and thrives in well-drained, somewhat dry soils, even those with limestone. When not in bloom, it remains attractive, forming beautiful dark green cushions with fine foliage in borders and on walls. This little treasure is perfect for dry or well-drained rock gardens, in full sun or partial shade.

Phlox subulata belongs to the Polemoniaceae family. This alpine perennial is native to the central and eastern United States. The 'Emerald Cushion Blue' cultivar forms a compact cushion of persistent foliage, resembling moss, reaching a height of 15 cm (6in). This plant can spread on the ground, forming a carpet with a diameter of 40 to 50 cm (16 to 20in). The abundant flowering occurs from May to June, sometimes as early as April depending on the climatic conditions, before the arrival of intense heat and summer drought. The plant becomes covered with thousands of small, 5-petaled flowers, light lavender-blue with a dark blue-violet center, measuring 2 to 2.5 cm (1in) in diameter. The dense foliage consists of tiny, linear, villous, dark green and fragrant leaves.

Phlox subulata 'Emerald Cushion Blue' is primarily a rock garden plant that complements stone well. Once established, it can withstand drought fairly well. Plant it en masse, alongside other pink or white varieties, aubrietas, campanula muralis, and Cerastium tomentosum. It will form a beautiful carpet at the base of dryland shrubs, such as lavender, gaura, cistus, shrubby cinquefoil, or Teucrium x Lucidrys. It also makes wonderful borders in well-drained soil. Its compact growth allows it to be grown in pots or hanging baskets, where it will gracefully cascade.