Emerald Blue Phlox (Phlox subulata 'Emerald Blue')
flox sub-yew-LAY-tah 'Emerald Blue'

Deciduous Perennial in the Polemoniaceae Family
Mat-forming groundcover with masses of blue flowers.

Emerald Blue is one of the most widely planted moss phlox cultivars, forming a dense, needle-leaved mat that disappears under a carpet of medium blue, five-petaled flowers each spring. An old, reliable heritage selection with no known breeder credit, it spreads readily by trailing stems and is a classic choice for rock gardens, walls, and slopes.

Pros

  • Dense, fast-spreading evergreen-ish groundcover mat
  • Reliable heavy spring bloom, drought-tolerant once established
  • Deer and rabbit resistant

Cons

  • Needs full sun for best bloom; thins out in shade
  • Can be confused in the trade with the similarly-named "Blue Emerald" - see auditnote
 

Plant Data

Mature Size 3 - 6 inches tall. 8 - 12 inches wide.
Growth Rate Moderate
Sun Exposure Full Sun - Full Sun
Moisture Tolerance Medium : Dry
Zones 3a - 9b (Usually hardy to -40° F)
Tags Adaptable, Attracts Butterflies, Attracts Hummingbirds, Attracts Pollinators, Attracts Wildlife, Container, Deciduous, Deer Resistant, Drought Tolerant, Edging, Fast Growth Rate, Filler, Formal Garden, Full Sun, Good for Borders, Good for Butterfly Garden, Good for Cottage Garden, Good for Mass Planting, Good for Rain Garden, Good for Rock Garden, Groundcover, Low Maintenance, Medium, Nativar, Non-Allergenic, Normal Soil, Perennial, Prairie Garden, Rabbit Resistant, Reblooms, Showy Flowers, Tolerant of Clay Soil, Tolerant of Hot Dry Site, Tolerant of Loamy Soil, Tolerant of Moist Soil, Tolerant of Poor Soil, Tolerant of Salt, Tolerant of Sandy Soil, Well-Drained Soil Blue or Purple Flowering Perennials, Deer Resistant Perennials, Ground Covers, Pink or Red Flowering Perennials, White Flowering Perennials
Bloom Period April - May
Flower Color Medium Blue
 

Most Popular Plants

 

More Info from Experts

Photos of This with...

Virginia Bluebells, Tsavo Yellow Ice Creeping Zinnia
 
Want More photos of this plant? Try Google Image Search!
 


Pricing and Availability History

Click a label to toggle visibility for that size

Past Availability
2025 : 04/03 - 10/04
2024 : 05/01 - 10/05
2023 : 04/13 - 09/30

© North Shore Plant Club 2026. Privacy Policy, Terms & Conditions.

Field-Grown vs. Greenhouse-Grown Plants

Plants which are well-adapted to our local climate are most often field-grown (outside). Field-grown plants are generally cheaper and have the advantage of already somewhat acclimated to our cold winters, but that means they’re not artificially far along in the spring and tend to bloom at the normal time in our area.

Spring annuals and tender perennials are typically grown in Greenhouses so they can be ready and luxurious exactly when customers want them. Some perennials are also “forced” into early bloom in greenhouses. In May, there can be a very big difference between field-grown and greenhouse-grown plants of the same type. The latter typically look good right away (so they’re a great choice where that’s important), but we typically pay a premium for it.


Estimated Recipe Cost

The cost of this recipe's ingredients will vary depending on the season and the sizes and varieties you select.


Benefits of Membership

Want a better way to get great plants and make your yard look awesome? Create your account below and get:

  • The best plants… from the same sources the pros use, but at near wholesale prices
  • More plants in more sizes than anywhere else… whether you’re looking for classics or rarities; annuals, perennials or shrubs; one plant or a whole yardful!
  • "No Contact" delivery or easy pick-up at a site near you without fighting the retail crowds. You choose!

Membership is free, but — since we rely on delivery and local pick-up — you have to live near one of our hubs (or be willing to drive to a site to pick them up). If you live farther away, and would like to help us bring the club to your neighbors, please email helpusgrow@northshoreplantclub.com.

Already a member?
Login
About Ordering From The Plant Club

To secure the best prices for club members and make sure we know the current plants available from each nursery, we take orders only a couple of times a month.

The next order is coming up soon. Here's a link to our ordering calendar. Shoot us an email at help@northshoreplantclub.com, and we'll be happy to talk about plants or let you know when it's time to buy them!


No Pricing or Availability Right Now

We order from a rotating cast of the best nurseries in the Great Lakes region. It looks like we've offered this plant in the past, but the nurseries we're working with this week don't appear to have it in stock at the moment.

Our goal is to bring as many plants together under "one roof" as possible, so we'll try hard to make it available again in the future!