FIRST IMPRESSIONS: Phlox subulata is a mat forming perennial wildflower with evergreen needle-like leaves. In spring foliage is covered by masses of starry violet, pinkish or white flowers. Creeping phlox is a fine groundcover for sunny gardens with moist well drained soil.
HABITAT & HARDINESS: Phlox subulata occurs in the eastern United States from Maine to Minnesota and south from Georgia and Louisiana.
This species is indigenous to rocky and sandy barrens, savannas, rocky ledges, slopes, clearings and disturbed sites.
Plants are hardy from USDA Zones 3-9.
PLANT DESCRIPTION: Phlox subulata is a diminutive groundcover that forms moss-like mats of evergreen foliage. The trailing stems are green when young turning tan and finally woody and knotty with age.
Leaves are awl shaped with smooth edges and pointed tips. Blades are needlelike and less than 1” long. They are opposite or clustered on the stems and are prickly to the touch.
Fertile stems terminate in showy flower clusters. The individual flowers are blue-violet, rosy-lavender, reddish or occasionally white.
Each flower has 5 petals with notched tips that flare from a narrow tube. The petals have dark markings toward the center.
Blooming begins in early or mid-spring and continues until early summer. Small inconspicuous oval seed capsules follow.
Flowering stems rise to 6” and plants spread to 2’.
CULTURAL & MAINTENANCE NEEDS: Phlox subulata flourishes in sun or part sun with average or dry well drained soil. Plants tolerate sandy or rocky soil, drought, neutral to slightly alkaline pH and poor infertile soil.
Plants are fairly pest resistant but may have issues with spider mites in hot dry sites. Foliage is somewhat resistant to deer but may be nibbled by rabbits.
Old stems become woody and tend to lose foliage and die out if they are not sheared after flowering to promote new growth. Intrusive growth of taller companions or weeds can overwhelm this sun-loving phlox and lead to decline.
In colder zones, plants are less likely to be burned by winter winds if they are protected by snow cover or an evergreen windbreak.
LANDSCAPE USES: This Groundcover produces colorful spring carpets of flowers in Perennial Borders or Rock Gardens. The species is particularly lovely if allowed to drape over a low retaining wall. Plants are used as Butterfly Nectar Plants, for Erosion Control or as part of a Grouping or Mass Planting. Phlox subulata has Showy Blooms and is appropriate for Cottage Gardens, Water-wise Landscapes and Low Maintenance Plantings.
COMPANION & UNDERSTUDY PLANTS: Try pairing Phlox subulata with Amsonia hubrichtii, Coreopsis major, Echinacea purpurea, Nepeta ‘Walker’s Low’ or Sporobolus heterolepis.
The cultivars, ‘Emerald Blue’ and ‘Emerald Pink’ have similar appearance and culture and could be substituted in some situations.
TRIVIA: Phlox subulata provides valuable early season nectar for swallowtail butterflies, day flying sphinx moths (like hummingbird moths and clearwing moths) and hummingbirds.
Due to similar growth habit and blooming time, Phlox subulata and Phlox stolonifera are sometimes confused. P. subulata has needle like foliage, flowers with dark markings toward the center, notched petals and a preference for sunny dry rocky habitats. P. stolonifera has oblong leaves, flowers without dark markings, rounded petals and a preference for moist woodland habitats.
For more information on this plant, visit the USDA PLANTS Database: http://plants.usda.gov/java/profile?symbol=PHSU3