North America Native Plant

Twelfth Rush

Botanical name: Juncus uncialis

USDA symbol: JUUN

Life cycle: annual

Habit: grass

Native status: Native to the lower 48 states  

Twelfth Rush: A Tiny Native Gem for Wetland Gardens Meet the twelfth rush (Juncus uncialis), a petite annual native that might just be the most overlooked plant in your local wetland. Don’t let its humble size fool you – this little rush packs a big punch when it comes to ...

Rare plant alert!

Region: Conservation status by state

Status: S3S4: Status is uncertain but is somewhere between the following rankings: 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 ⚘ Apparently Secure: Uncommon but not rare, and usually widespread. Possibly cause for longterm concern. Typically more than 100 occurrences in the state or more than 10,000 individuals ⚘

Twelfth Rush: A Tiny Native Gem for Wetland Gardens

Meet the twelfth rush (Juncus uncialis), a petite annual native that might just be the most overlooked plant in your local wetland. Don’t let its humble size fool you – this little rush packs a big punch when it comes to supporting healthy aquatic ecosystems in the western United States.

What Makes Twelfth Rush Special?

Twelfth rush is a delicate, grass-like annual that belongs to the rush family (Juncaceae). As its name suggests, it’s quite small – think of it as the pixie of the wetland world. This native charmer produces thin, wiry stems that create a fine-textured appearance in wet areas.

While it may not win any beauty contests for showy flowers or dramatic foliage, twelfth rush has its own quiet appeal. Its understated presence adds a natural, authentic look to wetland plantings that you simply can’t achieve with more ornamental species.

Where Does It Call Home?

This western native has made itself at home across four states: California, Nevada, Oregon, and Washington. It’s perfectly adapted to the unique climate and soil conditions of the American West, making it an excellent choice for gardeners in these regions who want to work with nature rather than against it.

A Word About Conservation

Here’s something important to know: twelfth rush has a conservation status of S3S4, which puts it in a somewhat vulnerable category. While it’s not critically endangered, this little rush deserves our attention and protection. If you’re interested in growing it, make sure to source your plants or seeds from reputable native plant nurseries that practice ethical collection methods.

Perfect for Wetland Gardens

Twelfth rush isn’t your typical garden center find, and that’s actually a good thing. This specialized native shines in specific situations:

  • Wetland restoration projects – It’s a natural choice for recreating authentic wetland habitats
  • Rain gardens – Helps manage stormwater while providing native habitat
  • Pond margins – Creates natural-looking edges around water features
  • Bog gardens – Perfect for those tricky wet spots in your landscape

Growing Conditions That Make It Happy

Here’s where twelfth rush gets particular – it’s all about the water. This plant has different wetland requirements depending on where it’s growing:

  • In the Arid West, it’s an obligate wetland plant, meaning it almost always needs wet conditions
  • In Western Mountains, Valleys, and Coast regions, it’s more flexible as a facultative wetland plant, tolerating some drier periods

For successful cultivation, provide:

  • Consistently moist to saturated soil
  • Full sun to partial shade
  • USDA hardiness zones 7-10
  • Neutral to slightly alkaline pH

Planting and Care Tips

Since twelfth rush is an annual, it completes its entire life cycle in one growing season. This actually makes it fairly low-maintenance once established:

  • Seeding: Direct sow seeds in fall or early spring in consistently moist soil
  • Watering: Keep soil consistently wet – this isn’t a plant for water-wise xeriscaping
  • Maintenance: Minimal care needed; allow plants to self-seed for natural regeneration
  • Harvesting seeds: Collect seeds in late summer if you want to expand your planting

Wildlife Value

While twelfth rush may not be a butterfly magnet, it serves important ecological functions. As part of wetland communities, it helps stabilize soil, filter water, and provides habitat structure for small wetland creatures. Its seeds may also provide food for waterfowl and other wetland birds.

Is Twelfth Rush Right for Your Garden?

This native rush isn’t for everyone, and that’s perfectly okay. Consider twelfth rush if you:

  • Have consistently wet areas in your landscape
  • Are passionate about native plant conservation
  • Want to create authentic wetland habitat
  • Appreciate subtle, naturalistic plantings
  • Live in California, Nevada, Oregon, or Washington

Skip it if you’re looking for showy flowers, drought-tolerant plants, or something for typical garden beds.

The Bottom Line

Twelfth rush may be small in stature, but it’s big in ecological importance. For the right gardener in the right location, this modest native can be a valuable addition to wetland gardens and restoration projects. Just remember to source it responsibly and give it the wet conditions it craves. Sometimes the most meaningful plants in our gardens are the ones that whisper rather than shout.

Twelfth 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 uncialis Greene - twelfth rush

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