Moss phlox
Phlox subulata · Polemoniaceae
📷 UpstateNYer · CC BY-SA 3.0
The gardener's calendar
Ideal time to plant moss phlox: set it out when the soil is neither frozen nor waterlogged, and water generously as it establishes.
ID card
- Scientific name
- Phlox subulata
- Family
- Polemoniaceae
- Plant type
- Herbaceous perennial ground cover
- Foliage
- Persistent, fine and linear
- Flowering
- April to June, star-shaped flowers in pink, white or purple
- Mature height
- Approximately 15 cm
- Spread
- 30 to 45 cm
- Hardiness
- Very hardy, down to -15°C
- Origin
- North America (mountainous regions)
✓ Taxonomy verifiedSource: AI estimate · hardiness: reliability high.
Expert tips
The key tip
Moss phlox thrives in dry, gravelly, well-aerated soil. After spring flowering, a very light trim (2-3 cm) keeps it from spreading into soft, loose clumps.
The common mistake
Planting it in rich, moist soil thinking you're pampering it: nope, it rots or turns into mushy green without charm, losing its generous flowering.
The pro's trick
Mix fine gravel or grit into the planting soil to keep the crown dry.
Care
Sunlight
Moss phlox thrives in full sun, ideally 6 to 8 hours of direct light per day. It tolerates light partial shade but will flower less densely. Place it in a well-exposed and airy location to prevent excessive foliage moisture.
Watering
Water moderately after planting to establish the roots. Once established, moss phlox is very drought-tolerant and only needs regular watering during prolonged periods without rain. Let the soil dry between waterings to prevent root rot.
Soil and drainage
Well-drained soil is essential: prefer light, poor to average substrate, slightly acidic to neutral. Amend with sand or gravel to improve natural drainage. Avoid overly rich and compact soils that encourage fungal diseases.
Pruning and cutting
After flowering (June-July), pinch back stems lightly to encourage compact, branched growth. Light pruning in late winter helps rejuvenate the plant. Remove dead wood or damaged parts in spring.
Fertilizing
Moss phlox demands little fertilizer thanks to its adaptation to poor soils. A light application of balanced fertilizer in spring is more than sufficient. Avoid excess nitrogen, which would promote foliage at the expense of flowering.
Diseases and pests
Generally hardy, it can be affected by powdery mildew or root rot in case of excess moisture. Ensure good drainage and sufficient air circulation. Aphids are occasional but rarely serious.
Did you know?
Moss phlox is a timeless classic in alpine gardens and European rock gardens since the nineteenth century. Its abundant flowers and vibrant colors earned it the nickname "flowering carpet" in gardening. Native to the Rocky Mountains, this hardy plant has spread throughout temperate gardens to create delicate color displays, especially in spring.
Where to buy it
Plant in spring or early autumn, avoiding spells of intense heat. Pick a plant with healthy foliage and roots that are not exposed. Best time: March, April, May, September.
Add this plant to my garden →Plants from the same family
- Jacob's ladderPolemonium caeruleum
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- Tufted phloxPhlox douglasii
- Woodland phloxPhlox divaricata
- Scarlet giliaIpomopsis aggregata
- Jacob's ladderPolemonium reptans
Tips generated and checked by Viridia — adapt them to your local climate.