Phlox subulata 'Emerald Blue' is a dense low growing mat forming perennial prized for its vibrant lavender blue flowers in early spring. It blankets slopes, rock gardens, and border edges with color while providing excellent erosion control. The needle like evergreen foliage remains attractive throughout the year making it an ideal groundcover for sunny dry areas.
Height & Spread: 4 - 6 in x 12 - 18 in
Bloom Time: Early to mid spring
Light Requirements: Full sun
Soil Preference: Well drained, sandy or rocky soil
Watering Needs: Low once established
Deer Resistance: Rarely browsed by deer or rabbits
Native Status
Phlox subulata is native to the eastern and central United States, thriving in rocky outcrops, slopes, and open woodland edges. The 'Emerald Blue' cultivar enhances its natural appeal with more intense flower color and dense matting habit.
WILDLIFE & INSECTS
Bees
- Provides abundant early season nectar to honeybees, bumblebees, and small native bees including Halictidae.
Butterflies
- Visited by spring butterflies such as Spring Azure and Eastern Tiger Swallowtail for nectar gathering.
Beneficial Insects
- Attracts hoverflies and predatory beetles that help control early garden pests during spring emergence.
Spacing & Landscape Use
Spacing Recommendations:
- Space 12 - 18 in apart to allow dense coverage and reduce weed competition in sun exposed areas.
Landscape Placement:
- Ideal for edging, slopes, rock gardens, or between stepping stones where its evergreen mats can trail and suppress weeds effectively.
Companion Plants
- Aurinia saxatilis (Basket of Gold) - A sun loving groundcover with golden spring flowers that contrast beautifully with the cool tones of 'Emerald Blue'.
- Veronica peduncularis 'Georgia Blue' - Low spreading blue flowered Veronica echoes the hues of Phlox while adding glossy foliage texture.
- Artemisia schmidtiana 'Silver Mound' - Fine textured silvery foliage creates a soft contrast to the dense mats of flowering phlox.
- Iberis sempervirens (Candytuft) - Crisp white early spring blooms brighten rock gardens and pair well with low growing blue phlox.
- Sedum spurium 'Dragon’s Blood' - Rich red succulent foliage and summer blooms extend color interest after the phlox has finished.