North America Native Plant

Twoflowered Rush

Botanical name: Juncus biglumis

USDA symbol: JUBI2

Life cycle: perennial

Habit: grass

Native status: Native to Alaska âš˜ Native to Canada âš˜ Native to Greenland âš˜ Native to the lower 48 states  

Twoflowered Rush: A Specialized Native for Wetland Gardens Meet the twoflowered rush (Juncus biglumis), a humble but hardy native plant that’s definitely not your typical garden showstopper. This perennial rush might not win any beauty contests, but it’s a true champion when it comes to wetland restoration and specialized garden ...

Twoflowered Rush: A Specialized Native for Wetland Gardens

Meet the twoflowered rush (Juncus biglumis), a humble but hardy native plant that’s definitely not your typical garden showstopper. This perennial rush might not win any beauty contests, but it’s a true champion when it comes to wetland restoration and specialized garden projects.

Where You’ll Find This Hardy Rush

The twoflowered rush is a cold-loving native that calls some pretty extreme places home. You’ll find it naturally occurring across Alaska, northern and western Canada (including Alberta, British Columbia, Manitoba, Ontario, Quebec, Yukon, Northwest Territories, Nunavut, and Labrador), plus Greenland. In the lower 48 states, it pops up in the high mountains of Colorado, Montana, New Mexico, and Wyoming, where it thrives in cool, wet conditions.

What Does It Look Like?

Don’t expect dramatic curb appeal from this little guy. The twoflowered rush grows as a rhizomatous perennial that reaches about 1 foot tall with medium-textured, green foliage. During summer, it produces small purple flowers that are honestly pretty inconspicuous – you might not even notice them unless you’re looking closely. The seeds that follow are brown and equally understated.

The Wetland Specialist

Here’s where things get interesting: this rush is what botanists call an obligate wetland plant across its entire range. That means it almost always occurs in wetlands – we’re talking constantly moist to saturated soils. If you’re dreaming of a low-maintenance perennial border, this probably isn’t your plant.

Growing Conditions That Make It Happy

The twoflowered rush is quite the specialist when it comes to its preferred growing conditions:

  • Temperature: Extremely cold hardy (down to -38°F!) and suited for USDA zones 1-4
  • Moisture: High moisture requirements – think bog garden levels
  • Soil: Adaptable to various soil textures but needs consistently wet conditions
  • pH: Prefers slightly acidic to neutral soils (5.0-7.5)
  • Light: Can handle intermediate shade
  • Drainage: Actually prefers poor drainage – the wetter, the better

Should You Plant It?

Here’s the honest truth: most gardeners probably shouldn’t attempt growing twoflowered rush. It’s a slow-growing plant with low seedling vigor, limited commercial availability, and very specific needs. However, there are some situations where it could be perfect:

  • Wetland restoration projects
  • Alpine or arctic-themed gardens in appropriate climates
  • Rain gardens in extremely cold regions
  • Bog gardens or water features
  • Native plant preservation efforts

Propagation and Care

If you’re determined to try growing this challenging native, here’s what you need to know:

  • Propagation is possible through seeds, bare root divisions, or sprigs
  • Seeds have low abundance and slow spread rates
  • Blooming and seed production occur in summer to fall
  • Growth rate is moderate once established
  • Requires at least 80 frost-free days
  • No commercial sources are readily available

Wildlife and Ecological Benefits

While the twoflowered rush might not attract butterflies like a showy native wildflower, it does provide some ecological benefits. Its small flowers offer nectar for various small insects, and the plant helps stabilize wet soils in its native habitats.

The Bottom Line

The twoflowered rush is undoubtedly an impressive survivor – any plant that thrives in arctic conditions deserves respect! However, unless you’re working on a specialized wetland project in zones 1-4, you’re probably better off choosing more garden-friendly native alternatives for your landscape. If you’re passionate about native plants and have the perfect boggy spot in a cold climate, it could be an interesting challenge for the adventurous gardener.

For most gardeners seeking wetland plants, consider exploring other native rushes, sedges, or wetland wildflowers that might be more readily available and better suited to typical garden conditions while still supporting local ecosystems.

Wetland Status

The rule of seasoned gardeners and landscapers is to choose the "right plant for the right place" matching plants to their ideal growing conditions, so they'll thrive with less work and fewer inputs. But the simplicity of this catchphrase conceals how tricky plant selection is. While tags list watering requirements, there's more to the story.

Knowing a plant's wetland status can simplify the process by revealing the interaction between plants, water, and soil. Surprisingly, many popular landscape plants are wetland species! And what may be a wetland plant in one area, in another it might thrive in drier conditions. Also, it helps you make smarter gardening choices and grow healthy plants with less care and feeding, saving you time, frustration, and money while producing an attractive garden with greater ecological benefits.

Regions
Status
Moisture Conditions

Alaska

OBL

Obligate Wetland - Plants with this status almost always occurs in wetlands

Arid West

OBL

Obligate Wetland - Plants with this status almost always occurs in wetlands

Western Mountains, Valleys, and Coast

OBL

Obligate Wetland - Plants with this status almost always occurs in wetlands

Twoflowered Rush

Classification

Group

Monocot

Kingdom

Plantae - Plants

Subkingdom

Tracheobionta - Vascular plants

Superdivision

Spermatophyta - Seed plants

Division

Magnoliophyta - Flowering plants

Subdivision
Class

Liliopsida - Monocotyledons

Subclass

Commelinidae

Order

Juncales

Family

Juncaceae Juss. - Rush family

Genus

Juncus L. - rush

Species

Juncus biglumis L. - twoflowered rush

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