The plant goes unnoticed during the year because it blends in with the grass and other surrounding parts of the landscape until flowers emerge in late winter and spring (Fig. 1). It is one of the signals that spring has arrived. Flower colors vary from red and lavender to pink and white, depending on the cultivar grown. Plants grow no more than about 6 inches tall, forming thick clumps and a good ground cover. The stiff leaves are narrow, growing to about an inch long and perhaps to 1/16 inch wide.
Scientific name: Phlox subulata
Pronunciation: flocks sub-yoo-LAY-tuh
Common name(s): creeping phlox, moss pink, moss phlox
Plant type: perennial; annual; herbaceous
USDA hardiness zones: 3B through 10 (Fig. 2)
Planting month for zone 7: Jun; Jul
Planting month for zone 8: May; Jun; Jul
Planting month for zone 9: Apr; May; Jun; Jul; Aug
Planting month for zone 10: Feb; Mar; Apr; May; Jun; Jul; Aug; Sep; Oct; Nov; Dec
Origin: native to North America
Uses: ground cover; cascading down a wall
Availability: generally available in many areas within its hardiness range
Height: .5 to 1 feet
Spread: depends upon supporting structure
Plant habit: spreading; prostrate (flat)
Plant density: moderate
Growth rate: moderate
Leaf arrangement: alternate
Leaf type: simple
Leaf margin: entire
Leaf shape: linear
Leaf venation: none, or difficult to see
Leaf type and persistence: deciduous
Leaf blade length: less than 2 inches
Leaf color: green
Fall color: not applicable
Fall characteristic: not applicable
Flower color: pink; lavender; white; red
Flower characteristic: spring flowering
Fruit shape: unknown
Fruit length: unknown
Fruit cover: unknown
Fruit color: unknown
Fruit characteristic: inconspicuous and not showy
Trunk and Branches
Trunk/bark/branches: not applicable
Current year stem/twig color: reddish
Current year stem/twig thickness: thin
Light requirement: plant grows in part shade/part sun
Soil tolerances: acidic; alkaline; sand; loam; clay
Drought tolerance: moderate
Soil salt tolerances: poor
Plant spacing: 12 to 18 inches
Roots: not applicable
Winter interest: no special winter interest
Outstanding plant: not particularly outstanding
Invasive potential: aggressive, spreading plant
Pest resistance: long-term health usually not affected by pests
Use and Management
Creeping phlox is suitable for rock gardens, ground covers, or for planting on top of a garden wall. Flowers and foliage will cascade down a container side, making a nice complement to an upright plant in the container. It makes a nice stabilizer for a sloping landscape.
Phlox should be located in the full sun for best growth. The plants benefit from fertilization and from regular irrigation in dry weather during the growing season. Cut the foliage back after flowering to encourage denser growth and perhaps a weak second flower display.
Cultivars include 'Crimson Beauty'—red flowers; 'Emerald Cushion'—pink flowers; 'Millstream'—white with a crimson eye; 'Millstream Daphne'—dark blue flowers; 'White Delight'—white flowers.
Propagation is by division of non-woody stems in early spring. Stem cuttings may be taken in summer or fall.
Pests and Diseases
Mites cause the foliage to lose its green color, especially in dry weather. Heavy infestations form fine webbing.
Leaf spots attack the leaves. Remove infected leaves as you notice them.
Powdery mildew is the most common disease on this plant. The disease causes a white powdery growth on the leaves.
Crown rot may cause rotting near the soil line. A white fungal growth forms on the stem bases. Remove infected plants.