Where does Red-Root Flat Sedge grow naturally?

Cyperus erythrorhizos is native to most US states from coast to coast, including the Southeast, Midwest, Great Plains, and parts of the West.

When does Red-Root Flat Sedge bloom?

This sedge produces flowers during the summer months of July, August, and September.

What growing conditions does Cyperus erythrorhizos prefer?

Red-Root Flat Sedge thrives in full sun locations with consistently high moisture or wet soil conditions.

Is Red-Root Flat Sedge actually a grass?

No, despite its grass-like appearance, Cyperus erythrorhizos is a sedge in the family Cyperaceae, not a true grass.

Is Red-Root Flat Sedge toxic to livestock?

The USDA PLANTS Database does not flag Red-Root Flat Sedge as toxic to livestock.

Is Red-Root Flat Sedge HOA-friendly?

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

Red-Root Flat Sedge

Name: Pollinator Patch
Author: Pollinator Patch

Cyperus erythrorhizos

Last reviewed: June 2026

Cyperus erythrorhizos is a native sedge found across most US states that blooms July through September in wet soils and full sun conditions.

Red-Root Flat Sedge (Cyperus erythrorhizos) — Photo: (c) Michael J. Papay, some rights reserved (CC BY), uploaded by Michael J. Papay

The USDA PLANTS Database (opens in new tab) does not flag Red-Root Flat Sedge as toxic to livestock.

Light

full sun

Water

high

Size

4"–16" H × 4"–12" W

Bloom

Jul, Aug, Sep

Native to

AL, AR, AZ, CA and 41 more states

Browse plants for this ecoregion

Coast Range Sierra Nevada Central California Valley Central California Foothills and Coastal Mountains Southern California Mountains Central Basin and Range Mojave Basin and Range Chihuahuan Deserts Central Oklahoma/Texas Plains Texas Blackland Prairies East Central Texas Plains Western Gulf Coastal Plain South Central Plains Sonoran Basin and Range

Red-rooted flatsedge is a small native sedge that forms low clumps with narrow, grass-like foliage. It produces small, reddish-brown flower clusters from summer through early fall and thrives in consistently moist to wet soils.

Growing Red-Root Flat Sedge

Grow Red-Root Flat Sedge in full sun and high water. Mature plants reach 4 to 16 inches tall and spread 4 to 12 inches wide. Expect high maintenance to keep it looking intentional in a front yard.

In an HOA neighborhood

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

Works well in: backyard only.

Requires consistently wet conditions difficult to maintain
Annual nature means gaps and replanting needs
Can appear weedy or unkempt to conventional gardeners

Wildlife value

This sedge provides seeds for waterfowl and songbirds, particularly in wetland margins. The plant structure offers habitat for small insects and arthropods in moist soil environments.

Common questions

Where does Red-Root Flat Sedge grow naturally?: Cyperus erythrorhizos is native to most US states from coast to coast, including the Southeast, Midwest, Great Plains, and parts of the West.
When does Red-Root Flat Sedge bloom?: This sedge produces flowers during the summer months of July, August, and September.
What growing conditions does Cyperus erythrorhizos prefer?: Red-Root Flat Sedge thrives in full sun locations with consistently high moisture or wet soil conditions.
Is Red-Root Flat Sedge actually a grass?: No, despite its grass-like appearance, Cyperus erythrorhizos is a sedge in the family Cyperaceae, not a true grass.
Is Red-Root Flat Sedge toxic to livestock?: The USDA PLANTS Database does not flag Red-Root Flat Sedge as toxic to livestock.
Is Red-Root Flat Sedge HOA-friendly?: Red-Root Flat Sedge takes more care to look intentional in a front yard. Consider it for backyard or mid-zone beds rather than the street edge.

Native range data from the USDA PLANTS Database and regional native plant society lists. Pollinator and host plant associations compiled from GBIF, iNaturalist, and published ecological literature.

Ready to grow Red-Root Flat Sedge? Add it to your garden in Pollinator Patch to track it and get season-by-season care guidance.

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