North America Native Plant

Boreal Phlox

Botanical name: Phlox sibirica borealis

USDA symbol: PHSIB

Life cycle: perennial

Habit: subshrub

Native status: Native to Alaska  

Synonyms: Phlox borealis Wherry (PHBO6)  âš˜  Phlox sibirica L. var. borealis (Wherry) B. Boivin (PHSIB2)   

Boreal Phlox: Alaska’s Rare Arctic Wildflower If you’re drawn to the idea of growing rare Arctic wildflowers, boreal phlox (Phlox sibirica borealis) might catch your attention. This uncommon native Alaskan perennial represents one of nature’s most specialized adaptations to extreme northern climates, though it’s definitely not your typical garden center ...

Rare plant alert!

Region: Conservation status by state

Status: S3?T3?: Status is uncertain but is somewhere between the following rankings: Inexact rank: ⚘ Vulnerable: Either very rare and local throughout its range, found only in a restricted range (even if abundant at some locations), or factors are making it vulnerable to extinction. Typically 21 to 100 occurrences or between 3,000 and 10,000 individuals ⚘ Subspecies or variety is vulnerable: Either very rare and local throughout its range, found only in a restricted range (even if abundant at some locations), or factors are making it vulnerable to extinction. Typically 21 to 100 occurrences or between 3,000 and 10,000 individuals. ⚘

Boreal Phlox: Alaska’s Rare Arctic Wildflower

If you’re drawn to the idea of growing rare Arctic wildflowers, boreal phlox (Phlox sibirica borealis) might catch your attention. This uncommon native Alaskan perennial represents one of nature’s most specialized adaptations to extreme northern climates, though it’s definitely not your typical garden center find.

What Makes Boreal Phlox Special

Boreal phlox is a perennial forb—essentially a non-woody flowering plant that returns year after year. Unlike its more common phlox cousins that grace temperate gardens, this Arctic specialist has evolved to thrive in Alaska’s challenging conditions. You might also see it listed under its synonyms Phlox borealis or Phlox sibirica var. borealis in botanical references.

Where You’ll Find It in the Wild

This rare wildflower calls Alaska home, where it grows in the state’s most northern regions. Its distribution is quite limited, making it a true specialist of Arctic and subarctic environments.

A Word About Rarity

Here’s something important to know: boreal phlox has a Global Conservation Status of S3?T3?, indicating its rarity and uncertain population status. This means if you’re considering adding it to your garden, you’ll want to be extra careful about sourcing. Only work with reputable native plant suppliers who can verify their plants come from responsibly collected or propagated stock—never collect from wild populations.

Growing Boreal Phlox: What to Expect

Let’s be honest—this isn’t a plant for beginners or most typical gardens. Boreal phlox has evolved for life in extremely cold conditions, likely thriving in USDA hardiness zones 1-3. If you live anywhere warmer, this Arctic beauty probably isn’t suited for your climate.

Ideal Growing Conditions

Based on its native habitat, boreal phlox likely prefers:

  • Extremely cold winter temperatures
  • Well-draining soil (Arctic plants can’t tolerate soggy conditions)
  • Full sun exposure
  • Rocky or gravelly soil types
  • Protection from hot summer temperatures

Garden Design Considerations

If you’re in the right climate zone and can source plants responsibly, boreal phlox would be perfect for:

  • Arctic or alpine garden themes
  • Rock gardens with excellent drainage
  • Native plant collections focusing on extreme climate adaptations
  • Educational gardens showcasing rare regional flora

The Bottom Line

Boreal phlox is fascinating from a botanical perspective, but it’s not practical for most gardeners. Its rarity, extremely specific climate requirements, and limited availability make it more of a conservation concern than a garden plant. If you’re passionate about Arctic plants and live in Alaska or similar climates, connect with local native plant societies or botanical gardens—they might have insights into responsible cultivation of this rare wildflower.

For most of us, appreciating boreal phlox means supporting conservation efforts and choosing more readily available native alternatives that provide similar garden benefits without impacting rare populations.

Boreal Phlox

Classification

Group

Dicot

Kingdom

Plantae - Plants

Subkingdom

Tracheobionta - Vascular plants

Superdivision

Spermatophyta - Seed plants

Division

Magnoliophyta - Flowering plants

Subdivision
Class

Magnoliopsida - Dicotyledons

Subclass

Asteridae

Order

Solanales

Family

Polemoniaceae Juss. - Phlox family

Genus

Phlox L. - phlox

Species

Phlox sibirica L. - Siberian phlox

Plant data source: USDA, NRCS 2025. The PLANTS Database. https://plants.usda.gov,. 2/25/2025. National Plant Data Team, Greensboro, NC USA