North America Native Plant

Snow Lichen

Botanical name: Stereocaulon incrustatum

USDA symbol: STIN60

Habit: lichen

Native status: Native to North America  

Snow Lichen: The Crusty Garden Visitor You Can’t Plant (But Should Appreciate) If you’ve ever noticed grayish-white, crusty patches growing on rocks, tree bark, or even bare soil in your garden, you might have encountered snow lichen (Stereocaulon incrustatum). But before you start wondering where to buy seeds or how ...

Snow Lichen: The Crusty Garden Visitor You Can’t Plant (But Should Appreciate)

If you’ve ever noticed grayish-white, crusty patches growing on rocks, tree bark, or even bare soil in your garden, you might have encountered snow lichen (Stereocaulon incrustatum). But before you start wondering where to buy seeds or how to propagate this interesting organism, here’s the scoop: you can’t actually plant or grow lichens like traditional garden plants!

What Exactly Is Snow Lichen?

Snow lichen isn’t a plant at all – it’s actually a fascinating partnership between fungi and algae living together in perfect harmony. This symbiotic relationship creates what looks like a crusty, branched organism that can survive in some pretty harsh conditions. The snow in its name comes from its grayish-white appearance that can resemble patches of old snow clinging to surfaces.

This particular lichen species is native to North America and can be found across northern regions where cool, moist conditions prevail. It’s especially common in boreal and arctic areas, though it can pop up in suitable microclimates further south.

How to Identify Snow Lichen

Spotting snow lichen in your garden or on nature walks is easier once you know what to look for:

  • Grayish-white to pale gray crusty appearance
  • Small coral-like branching structures called pseudopodetia that stick up from the main body
  • Grows directly on rocks, soil, tree bark, or other hard surfaces
  • Forms irregular patches that can range from tiny spots to larger colonies
  • Feels rough and crusty to the touch (though it’s best to observe rather than handle)

Is Snow Lichen Beneficial in Your Garden?

While you can’t cultivate snow lichen, its presence in your garden is actually a good sign! Here’s why you should appreciate these crusty little communities:

  • Air quality indicator: Lichens are sensitive to air pollution, so their presence suggests you have relatively clean air
  • Soil stabilization: They help prevent erosion on bare soil and rock surfaces
  • Ecosystem contribution: They provide food and nesting materials for some small wildlife
  • Natural beauty: They add subtle texture and interest to rock gardens and natural areas

Why You Can’t Grow Snow Lichen

Unlike your typical garden plants, lichens can’t be purchased, planted, or propagated through normal gardening methods. They:

  • Require specific environmental conditions that can’t be artificially created
  • Grow extremely slowly – we’re talking years or decades to establish
  • Need the perfect balance of moisture, air quality, and substrate
  • Don’t respond to fertilizers, watering, or other garden care

Encouraging Natural Lichen Growth

While you can’t plant snow lichen, you can create conditions that might encourage it and other lichens to appear naturally:

  • Avoid using chemical pesticides and fertilizers that can harm sensitive organisms
  • Maintain good air quality around your property
  • Leave some natural rock surfaces and mature tree bark undisturbed
  • Be patient – lichens appear on their own timeline, not yours!

The Bottom Line

Snow lichen is one of those garden visitors that shows up on its own terms. While you can’t add it to your shopping list or plant it in your flower beds, discovering it growing naturally in your garden is like receiving a stamp of approval from nature itself. It’s telling you that your outdoor space has clean air and suitable conditions for these remarkable organisms to thrive.

So next time you spot those crusty, grayish patches on your rocks or trees, take a moment to appreciate these slow-growing survivors. They’ve been around much longer than our gardens, and they’ll likely be there long after we’re gone – a humble reminder of nature’s incredible ability to adapt and persist.

Snow Lichen

Classification

Group

Lichen

Kingdom

Fungi - Fungi

Subkingdom
Superdivision
Division

Ascomycota - Sac fungi

Subdivision
Class

Ascomycetes

Subclass
Order

Lecanorales

Family

Stereocaulaceae Chevall.

Genus

Stereocaulon Hoffm. - snow lichen

Species

Stereocaulon incrustatum Flörke - snow lichen

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