Polar Willow: The Ultimate Cold-Weather Ground Cover
If you think your winters are tough, wait until you meet the polar willow (Salix polaris). This incredibly hardy little shrub laughs in the face of temperatures that would make a penguin shiver, thriving in some of the coldest places on Earth. But before you get excited about adding this arctic warrior to your garden, let’s explore whether this extreme cold-weather specialist is right for you.
What is Polar Willow?
Polar willow is a perennial shrub that’s about as far from your typical backyard willow as you can get. Instead of growing tall and graceful by a pond, this tough little plant hugs the ground, reaching only about 2.4 inches (0.2 feet) in height. It spreads through underground rhizomes to form dense mats, making it nature’s own arctic carpet.
This remarkable plant goes by several scientific names in botanical circles, including Salix pseudopolaris and various subspecies, but Salix polaris is the name that sticks.
Where Does Polar Willow Call Home?
Polar willow is native to the extreme northern regions of North America, specifically Alaska and Canada. You’ll find it growing wild in Alaska, British Columbia, Yukon, Northwest Territories, and Nunavut – basically, places where chilly is an understatement.
The Reality Check: Is This Plant for You?
Here’s where we need to have an honest conversation. Unless you’re gardening in USDA hardiness zones 1-3 (think northern Alaska or arctic Canada), polar willow probably isn’t your best choice. This plant doesn’t just prefer cold – it absolutely requires it. With a minimum temperature tolerance of -62°F, it’s built for conditions that would be fatal to most other plants.
The polar willow also has some pretty specific needs:
- Requires a minimum of 47 frost-free days (most places have way more than this)
- Thrives in wetland conditions but can handle some drying
- Needs coarse to medium-textured, well-draining soils
- Prefers low fertility conditions
What Does Polar Willow Look Like?
Don’t expect showy flowers or dramatic foliage with this one. Polar willow is all about function over form:
- Grows in a low, spreading mat formation
- Produces small, inconspicuous purple catkins in spring
- Has coarse-textured green foliage
- Moderate growth rate once established
- Forms dense ground cover through rhizomatous spread
Wildlife and Pollinator Benefits
In its native arctic habitat, polar willow plays an important role in the ecosystem. Its early spring catkins provide crucial nectar for arctic insects emerging from winter, and the dense mat formation offers shelter for small wildlife. The plant produces abundant seeds that spread rapidly, helping to colonize and stabilize soil in harsh conditions.
Growing Polar Willow (If You’re in the Right Climate)
If you happen to garden in the arctic or subarctic regions where this plant naturally thrives, here’s what you need to know:
Propagation
- Can be grown from seed (no cold stratification required, surprisingly)
- Propagates easily from cuttings
- Can also be started from sprigs
Planting Conditions
- Plant in coarse or medium-textured soils
- Ensure good drainage despite its wetland tolerance
- Choose locations with pH between 5.5-8.5
- Plant 320-1,280 plants per acre for ground cover applications
Care and Maintenance
The good news? Once established, polar willow is remarkably low-maintenance. It has low fertility requirements, moderate drought tolerance for short periods, and will resprout if damaged. Just don’t expect it to live forever – it has a relatively short lifespan compared to other shrubs.
The Bottom Line
Polar willow is truly a plant for specialists. If you’re gardening in the extreme north and need a hardy ground cover that can handle the harshest conditions imaginable, this could be your plant. For everyone else, it’s better admired from afar (or through nature documentaries).
For most gardeners looking for cold-hardy ground covers, consider native alternatives suited to your specific region instead. Your local native plant society can help you find species that will thrive in your climate while supporting local wildlife.
Sometimes the most interesting plants are the ones that remind us just how diverse and specialized nature can be – even if we can’t grow them in our own backyards.
