FIRST IMPRESSIONS: Phlox stolonifera is a lovely mat forming perennial wildflower. Plants have evergreen oval or oblong deep green leaves. In late spring or early summer, foliage is crowned by loose clusters of showy lavender flowers. Creeping phlox is a fine groundcover for partly shaded woodlands or gardens with moist well drained soil.
HABITAT & HARDINESS: Phlox stolonifera occurs in the eastern United States in Maine and Vermont and from New York west to Ohio and south to Alabama.
This species is indigenous to rich deciduous woodlands, stream banks, open woods and shaded rocky slopes mostly in the Appalachian Mountains.
Plants are hardy from USDA Zones 5-9.
PLANT DESCRIPTION: Phlox stolonifera is a diminutive stoloniferous groundcover that forms loose mats of semi-evergreen foliage.
Leafy stems creep along the ground and branch to form upright flowering stems.
The opposite leaves are oblong with smooth edges and blunt or pointed tips. Blades average 3” on sterile stems and ¾” on flowering stems.
Fertile stems terminate in showy rounded 6” flower cymes. Florets are fragrant with 5 flat blue-violet, rosy-lavender or occasionally white petals. The petals are rounded and they flare from a narrow tube.
Blooming begins in mid-spring continuing until early summer. Small inconspicuous oval seed capsules follow.
Flowering stems rise to 8”. Plants spread to 2’ gradually forming colonies from short rhizomes and spreading stems that root at the nodes.
CULTURAL & MAINTENANCE NEEDS: Phlox stolonifera flourishes in bright shade with moist rich well drained soil. Plants tolerate acid or alkaline pH, drought, part sun and dry shade.
This species is fairly pest resistant but needs good air circulation and deadheading to prevent issues with powdery mildew. Spider mites can cause problems in hot dry sites. Slugs can become a pest in overly moist sites. Plants are somewhat resistant to deer but may be nibbled by rabbits.
The most difficult cultural issue with this species is choosing a suitable site. In appropriate situations with some shade and very good drainage, plants are vigorous and very easy to grow.
This species often self-sows if conditions are good.
In garden situations, plants benefit from an occasional fertilization and deadheading when flowers wane.
LANDSCAPE USES: This is a good Groundcover for a Perennial Border or Shade Garden. Plants are also used as Butterfly Nectar Plants or as part of a Grouping or Mass Planting. In mild climates attractive rosettes provide Winter Interest. Phlox stolonifera has Showy Blooms and is appropriate for Cottage Gardens, Water-wise Landscapes, Low Maintenance Plantings and Rock Gardens.
COMPANION & UNDERSTUDY PLANTS: Try pairing Phlox stolonifera with Aquilegia canadensis, Carex albicans, Carex plantaginea, Heuchera americana 'Dales Strain', Dryopteris marginalis or Polystichum acrostichoides.
Phlox divaricata has similar appearance and culture and could be substituted in some situations.
TRIVIA: Phlox stolonifera provides valuable early season nectar for swallowtail butterflies, day flying sphinx moths (hummingbird moths and clearwing moths) and hummingbirds.
Like Phlox divaricata, this species has fertile and infertile stems. The flowering fertile shoots die back after producing seed. Infertile non-flowering stems persist through the growing season and fuel the following year’s growth.
In 1990, Phlox stolonifera became the first plant selected by the Perennial Plant Association as Perennial Plant of the Year.
For more information on this plant, visit the USDA PLANTS Database: http://plants.usda.gov/java/profile?symbol=PHST3