Product Field NotesCompanion Plants
Blue Emerald Creeping Phlox: A Soft Blue Mat for Spring Edges
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Blue Emerald creeping phlox is a long-grown favorite that covers itself in soft lilac-blue flowers each spring. The small, notched blooms, each with a tiny darker eye, pack in so tightly they hide the foliage completely. After bloom, the bright green, needle-like leaves stay as a neat evergreen mat.
It is hardy to zone 2, which means it shrugs off winters that make the rest of us complain.
Blue Emerald at a glance
| Trait | What to expect |
|---|---|
| Botanical name | Phlox subulata 'Blue Emerald' |
| Flowers | About ¾ inch, soft lilac-blue with a small darker eye |
| Foliage | Bright green, needle-like, evergreen mat |
| Size | 4 to 6 inches tall, 12 to 18 inches wide |
| Bloom | Starts late April, peaks early May |
| Hardiness | USDA zones 2 to 9 |
| Light | Full sun |
| Wildlife | Good for butterflies and bees; moderately deer resistant |
A cool blue edge for lavender
Many creeping phlox come in pinks and magentas. Blue Emerald's lilac-blue is gentler and sits close to lavender's own palette, so a bed edged with it looks calm and connected. It blooms in late April and early May, weeks before the lavender, and then the green mat gives the bed a tidy border all summer and winter.
It shares lavender's need for sun and good drainage, so plant it right along the front edge. Keep it a few inches from the lavender's woody base so the mat does not hold moisture against the crown. On slopes, in rock gardens and along stone walls, its trailing stems root as they spread and help hold soil.
Planting and care
- Site: full sun, average well-drained soil. It dislikes soggy ground.
- Spacing: about 12 to 18 inches apart for a mat that knits together.
- Water: regularly at first, then only in long hot, dry spells so it does not brown out.
- After bloom: shear back by about a third to keep it dense and tidy.
- Winter: foliage stays green or bronzes. Do not pile leaves or mulch on the mat, and trim out winter-browned patches in spring.
Good drainage prevents most problems. In hot, dry weather, keep an eye out for spider mites.
Plug tray or bare root
Blue Emerald is offered as a 72-cell plug tray for edging long beds or planting a slope, and as a bare root plant for smaller spaces. See each product page for current availability and the Wholesale Hub for tray orders.
Frequently asked questions
Is Blue Emerald really blue?
It is a soft lilac-blue, more lavender-blue than true blue, which is why it pairs so well with lavender.
Does it stay green all year?
The needle-like foliage stays green or bronzes slightly over winter, then greens up in spring.
How fast does it spread?
Its trailing stems root as they go, filling in to 12 to 18 inches across.
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