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: August 2026

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

Toxicity unknown

Red-Root Flat Sedge (Cyperus erythrorhizos) 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 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

Before you buy

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Cities and water utilities offer rebates for replacing lawn with native and water-wise plants. We track 445 programs across 44 states, each with a link to the provider and the date we last checked it.

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Browse plants for this ecoregion

Coast Range Marine West Coast Forest Sierra Nevada Central California Foothills and Coastal Mountains Central California Valley Southern California Mountains Northwestern Forested Mountains North American Deserts Central Basin and Range Mojave Basin and Range Chihuahuan Deserts High Plains Central Great Plains Great Plains Cross Timbers Texas Blackland Prairies East Central Texas Plains Western Gulf Coastal Plain South Central Plains Eastern Temperate Forests Ozark Highlands Central Irregular Plains Northwestern Great Plains Piedmont Northern Glaciated Plains Western Corn Belt Plains Northern Lakes and Forests North Central Hardwood Forests Driftless Area Southeastern Wisconsin Till Plains Central Corn Belt Plains Eastern Corn Belt Plains Southern Michigan/Northern Indiana Drift Plains Northeastern Coastal Zone Erie Drift Plain Middle Atlantic Coastal Plain Northern Piedmont Southeastern Plains Ridge and Valley Western Allegheny Plateau Interior Plateau Interior River Valleys and Hills Mississippi Alluvial Plain Mississippi Valley Loess Plains Southern Coastal Plain Sonoran Basin and Range Eastern Great Lakes Lowlands Atlantic Coastal Pine Barrens Southern California/Northern Baja Coast

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.

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

Native range data from vouchered herbarium specimen records 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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