Where does American Mannagrass naturally grow?

Glyceria grandis is native to most U.S. states from coast to coast, including Arizona, California, Colorado, and throughout the Northeast, Midwest, and Mountain West regions.

What growing conditions does American Mannagrass prefer?

This wetland grass thrives in consistently moist to wet soils and can tolerate partial sun to partial shade conditions. It naturally occurs in marshes, pond edges, and wet meadows.

When does American Mannagrass bloom?

Glyceria grandis produces its grass flowers during the summer months of June, July, and August.

How tall does American Mannagrass grow?

This perennial grass typically grows 3 to 5 feet tall, forming clumps or colonies in suitable wetland habitats.

Is American Mannagrass HOA-friendly?

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

American Mannagrass

Name: Pollinator Patch
Author: Pollinator Patch

Glyceria grandis

Last reviewed: June 2026

American Mannagrass (Glyceria grandis) is a native wetland grass found across most U.S. states that blooms from June through August in wet soils and shallow water.

Light

part sun

Water

high

Size

24"–60" H × 12"–24" W

Bloom

Jun, Jul, Aug

Native to

AZ, CA, CO, CT and 33 more states

Browse plants for this ecoregion

Coast Range Sierra Nevada Central Basin and Range

American mannagrass is a tall native wetland grass that forms upright clumps with narrow green leaves. It produces delicate seed heads in summer and thrives in consistently moist to wet soils.

Growing American Mannagrass

Grow American Mannagrass in part sun and high water. Mature plants reach 24 to 60 inches tall and spread 12 to 24 inches wide. Expect moderate maintenance to keep it looking intentional in a front yard.

In an HOA neighborhood

American Mannagrass 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.

Requires consistently wet conditions that may create drainage concerns
Can appear wild and unkempt compared to typical landscape grasses
May spread aggressively in suitable wet conditions

Wildlife value

The seeds provide food for waterfowl and songbirds, while the dense clumps offer nesting habitat for wetland birds.

Common questions

Where does American Mannagrass naturally grow?: Glyceria grandis is native to most U.S. states from coast to coast, including Arizona, California, Colorado, and throughout the Northeast, Midwest, and Mountain West regions.
What growing conditions does American Mannagrass prefer?: This wetland grass thrives in consistently moist to wet soils and can tolerate partial sun to partial shade conditions. It naturally occurs in marshes, pond edges, and wet meadows.
When does American Mannagrass bloom?: Glyceria grandis produces its grass flowers during the summer months of June, July, and August.
How tall does American Mannagrass grow?: This perennial grass typically grows 3 to 5 feet tall, forming clumps or colonies in suitable wetland habitats.
Is American Mannagrass HOA-friendly?: American Mannagrass 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 American Mannagrass? Add it to your garden in Pollinator Patch to track it and get season-by-season care guidance.

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