Atlantic Mannagrass
Glyceria obtusa
Last reviewed: June 2026
The USDA PLANTS Database (opens in new tab) does not flag Atlantic Mannagrass as toxic to livestock.
Light
part sun
Water
high
Size
12"–36" H × 6"–18" W
Bloom
Jun, Jul, Aug
Native to
CT, DE, MA, MD and 9 more states
Atlantic mannagrass is a native wetland grass that forms clumps of narrow green leaves and produces delicate flower spikes in summer. This moisture-loving perennial thrives in consistently wet soils and partial sun conditions. It works well for rain gardens, pond edges, and other water-retention areas.
In an HOA neighborhood
Atlantic Mannagrass takes more care to keep looking intentional in a front yard. Maintenance level: low. Consider it for backyard or mid-zone beds rather than the street edge.
Works well in: backyard only.
- Requires consistently wet conditions that may appear problematic
- Can look unkempt or weedy to conventional standards
- Associated with wetland areas rather than traditional landscaping
Wildlife value
The seeds provide food for waterfowl and songbirds, while the dense growth offers nesting habitat for marsh birds. As a native grass, it supports various insects and contributes to wetland ecosystem health.
Common questions
- How much sun does Atlantic Mannagrass need?
- Atlantic Mannagrass grows best in part sun conditions.
- When does Atlantic Mannagrass bloom?
- Atlantic Mannagrass blooms in June, July, and August.
- Where is Atlantic Mannagrass native?
- Atlantic Mannagrass (Glyceria obtusa) is native to CT, DE, MA, MD and 9 more states, per the USDA PLANTS Database and regional native plant society lists.
- Is Atlantic Mannagrass toxic to livestock?
- The USDA PLANTS Database does not flag Atlantic Mannagrass as toxic to livestock.
- Is Atlantic Mannagrass HOA-friendly?
- Atlantic 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 Atlantic Mannagrass? Add it to your garden in Pollinator Patch to track it and get season-by-season care guidance.
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