North America Native Plant

Knotted Rush

Botanical name: Juncus nodosus var. nodosus

USDA symbol: JUNON

Life cycle: perennial

Habit: grass

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

Knotted Rush: A Hardy Native Grass for Wet Areas If you’ve been searching for a native plant that can handle soggy soils and still look graceful, meet the knotted rush (Juncus nodosus var. nodosus). This unassuming perennial grass might not win any flashy flower contests, but it’s a workhorse that ...

Rare plant alert!

Region: New Jersey

Status: Highlands Listed, S3: New Jersey Highlands region ⚘ 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 ⚘

Knotted Rush: A Hardy Native Grass for Wet Areas

If you’ve been searching for a native plant that can handle soggy soils and still look graceful, meet the knotted rush (Juncus nodosus var. nodosus). This unassuming perennial grass might not win any flashy flower contests, but it’s a workhorse that deserves a spot in every water-wise gardener’s toolkit.

What Makes Knotted Rush Special?

Knotted rush gets its common name from the distinctive swollen nodes that interrupt its slender, upright stems. These knots give the plant a subtle textural interest that’s quite charming once you notice them. As a member of the rush family, this grass-like perennial brings a naturalistic, almost meadow-like quality to garden spaces.

A True North American Native

One of the best things about knotted rush is its impressive native credentials. This plant calls Alaska, Canada, and the lower 48 states home, making it a truly continental species. You’ll find it growing naturally across an enormous range of states and provinces, from Alberta and British Columbia all the way down to Texas and from Maine to California.

However, if you’re gardening in New Jersey, take note: knotted rush has a rarity status of Highlands Listed, S3 in the state. This means it’s uncommon and deserves our conservation attention. If you’re a New Jersey gardener interested in growing this plant, make sure to source it responsibly from reputable native plant nurseries rather than collecting from wild populations.

Where Knotted Rush Shines in Your Garden

This isn’t a plant for formal flower borders or drought-tolerant xeriscapes. Knotted rush loves moisture and thrives in areas that many other plants would find challenging:

  • Rain gardens and bioswales
  • Pond and stream margins
  • Wetland restoration projects
  • Native plant gardens with consistent moisture
  • Naturalized meadow areas

Its subtle presence makes it an excellent supporting player rather than a star performer. Think of knotted rush as the reliable friend who makes everyone else look good while quietly doing important work behind the scenes.

Growing Conditions and Care

The good news for busy gardeners is that knotted rush is refreshingly low-maintenance once established. Here’s what it needs to thrive:

Moisture: This plant loves consistently moist to wet soils. It can handle seasonal flooding and won’t complain about soggy conditions that would rot other plants.

Light: Full sun to partial shade works well, though it tends to be most vigorous in sunny locations.

Climate: Hardy in USDA zones 3-9, making it suitable for most of temperate North America.

Planting and Maintenance Tips

Getting knotted rush established is straightforward. Plant it in spring after the last frost, spacing plants about 12-18 inches apart if you’re creating a naturalized planting. Water regularly during the first growing season to help establish the root system.

Once established, this perennial is remarkably self-sufficient. It doesn’t require fertilization and actually prefers lean soils. You can cut back the stems in late winter or early spring if you prefer a tidier look, but many gardeners leave them standing for winter interest and to provide habitat for beneficial insects.

Wildlife and Ecological Value

While knotted rush may not be a major pollinator magnet (it’s wind-pollinated), it serves important ecological functions. The dense root systems help prevent soil erosion, and the seeds provide food for various bird species. The plant also offers shelter and nesting sites for small wildlife in naturalized settings.

Should You Plant Knotted Rush?

If you have a wet or consistently moist area in your landscape, knotted rush deserves serious consideration. It’s particularly valuable for gardeners interested in native plants, ecological restoration, or managing stormwater runoff. Just remember to source plants responsibly, especially if you’re in areas where it has conservation concerns.

This isn’t a plant that will stop traffic with showy blooms, but it will quietly and reliably fill an important niche in your garden ecosystem. Sometimes the most valuable plants are the ones that simply do their job well, year after year.

Knotted 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 nodosus L. - knotted rush

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