Emerald Blue Moss Phlox

Light Needs

Partial Shade to Full Sun

(At Least 3 Hours of Direct Sunlight)

Mature Height

6-11 Inches

Mature Spread

2-3 Feet

Growing Zones

3 to 8

Emerald Blue Moss Phlox (creeping phlox) blooms abundantly and forms a solid groundcover, even in tricky sites. In the spring, it is smothered in fragrant, star-shaped, blue-violet blossoms. The blooms continue until early summer and attract butterflies. The evergreen foliage is needle-like and resembles moss, accounting for the common name. This phlox forms a spreading mat that suppresses weeds and requires little maintenance.  

Emerald Blue grows as a low, dense mound, only 3 – 6 inches high. It spreads quickly to 2 – 3 feet wide, working well as a flowering groundcover. Its parent species Phlox subulata is native to the eastern United States and is commonly found in sandy pine or oak barrens. Emerald Blue is not appealing to deer but could be nibbled by rabbits. It tolerates heat and humidity, and poor, dry soils. Use it as an easy groundcover in a rock garden, or let it cascade over a retaining wall or slope. It also makes a cheerful ‘spiller’ in outdoor container plantings.

Emerald Blue Moss Phlox Care

This phlox performs best in full sun with at least 6 hours of direct sunlight a day, although it may need some afternoon shade in hot summer climates. It prefers moist, well-drained soil, but also can be grown in dry, rocky, and sandy soils. Water new plants regularly during the summer months to establish a strong root system. Established plants will not need much supplemental water in the summer. Apply a layer of high-quality compost to keep the root system from drying out.

After blooming, shear the plant back by half to maintain a compact, tidy appearance. Clean up any tattered foliage in the spring. Phlox can be divided every 3-5 years in spring or fall.

Emerald Blue Moss Phlox Spacing

To plant a solid groundcover, space each plant approximately 2 feet apart on center, in staggered rows. For container plantings, select a frost-proof pot at least 18 inches in diameter with large drainage holes.