What growing conditions does Dulichium arundinaceum prefer?

Threeway sedge grows best in shallow standing water or consistently saturated soil along pond edges, marshes, and slow streams, in full sun to partial shade.

When does Dulichium arundinaceum bloom?

It blooms from June through August, producing small, inconspicuous greenish brown flower spikes along its jointed stems.

What does Dulichium arundinaceum look like?

It has hollow, jointed stems with narrow leaves arranged in a distinctive three ranked, stacked pattern, giving the plant a grass-like appearance despite being a sedge.

Is Dulichium arundinaceum a good choice for a rain garden or pond margin?

Yes, because it tolerates standing water and constantly wet soil, it works well planted at pond edges, in bog gardens, or in the wettest zones of a rain garden.

Is Threeway Sedge toxic to livestock?

The USDA PLANTS Database does not flag Threeway Sedge as toxic to livestock.

Is Threeway Sedge HOA-friendly?

Threeway Sedge takes more care to look intentional in a front yard. Consider it for backyard or mid-zone beds rather than the street edge.

Threeway Sedge

Name: Pollinator Patch
Author: Pollinator Patch

Dulichium arundinaceum

Last reviewed: August 2026

Dulichium arundinaceum, or threeway sedge, is a grass-like wetland plant that grows in shallow water and marshy soil, blooming with small greenish flower spikes from June through August.

Toxicity unknown

Threeway Sedge (Dulichium arundinaceum) is not listed by the ASPCA Animal Poison Control Center (opens in new tab) or the other sources we check, so we have no verdict for it either way. Absence from those lists is not a clearance. If your pet shows symptoms after eating any plant, call the ASPCA at (888) 426-4435.

The USDA PLANTS Database (opens in new tab) does not flag Threeway Sedge as toxic to livestock.

Light

part sun

Water

high

Size

12"–36" H × 6"–18" W

Bloom

Jun, Jul, Aug

Native to

AL, AR, CA, CT and 36 more states

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Threeway sedge is a native wetland grass that forms upright clumps with narrow, arching leaves. It produces small brown flower clusters in summer and thrives in consistently moist to wet soil conditions. This sedge works well in rain gardens, pond edges, and other water-retentive areas.

Growing Threeway Sedge

Grow Threeway Sedge in part sun and high water. Mature plants reach 12 to 36 inches tall and spread 6 to 18 inches wide. Expect moderate maintenance to keep it looking intentional in a front yard.

In an HOA neighborhood

Threeway Sedge takes more care to keep looking intentional in a front yard. Maintenance level: moderate. Consider it for backyard or mid-zone beds rather than the street edge.

Works well in: backyard only.

Looks very wild and unmanicured
Requires constant moisture which can create muddy conditions
May appear weedy to those unfamiliar with native sedges

Wildlife value

This sedge provides habitat and nesting material for waterfowl and supports various insects. The seeds are eaten by ducks and other water birds.

Common questions

What growing conditions does Dulichium arundinaceum prefer?: Threeway sedge grows best in shallow standing water or consistently saturated soil along pond edges, marshes, and slow streams, in full sun to partial shade.
When does Dulichium arundinaceum bloom?: It blooms from June through August, producing small, inconspicuous greenish brown flower spikes along its jointed stems.
What does Dulichium arundinaceum look like?: It has hollow, jointed stems with narrow leaves arranged in a distinctive three ranked, stacked pattern, giving the plant a grass-like appearance despite being a sedge.
Is Dulichium arundinaceum a good choice for a rain garden or pond margin?: Yes, because it tolerates standing water and constantly wet soil, it works well planted at pond edges, in bog gardens, or in the wettest zones of a rain garden.
Is Threeway Sedge toxic to livestock?: The USDA PLANTS Database does not flag Threeway Sedge as toxic to livestock.
Is Threeway Sedge HOA-friendly?: Threeway Sedge takes more care to look intentional in a front yard. Consider it for backyard or mid-zone beds rather than the street edge.

These answers were drafted with an AI model from this plant's data. Verify care details with a local expert.

Native range data from the World Checklist of Vascular Plants (Kew). Pollinator and host plant associations compiled from GBIF, iNaturalist, and published ecological literature.

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