Rattlesnake Grass
Glyceria canadensis
Last reviewed: August 2026
Glyceria canadensis (Rattlesnake Grass) is a native wetland grass found across northeastern and midwestern North America. This moisture-loving perennial blooms from June through August in partially shaded wet areas.
Toxicity unknown
Rattlesnake Grass (Glyceria canadensis) 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 Rattlesnake Grass as toxic to livestock.
Light
part shade
Water
high
Size
24"–48" H × 12"–24" W
Bloom
Jun, Jul, Aug
Native to
CT, DE, IL, IN and 17 more states
Before you buy
Your city may pay you to plant this
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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Rattlesnake grass is a native wetland grass that thrives in consistently moist to wet soils and partial shade. This clumping perennial produces delicate flower panicles in summer and provides texture in water gardens or rain gardens. It goes dormant in winter, leaving brown stems that can be cut back in late winter or early spring.
Growing Rattlesnake Grass
Grow Rattlesnake Grass in part shade and high water. Mature plants reach 24 to 48 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
Rattlesnake Grass 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 are uncommon in typical yards
- Can appear unkempt when dormant
- Tall growth habit may look too wild for front yard use
Wildlife value
This grass provides nesting material and seeds for birds, particularly waterfowl and songbirds. The dense clumps offer shelter for small wildlife in wetland areas.
Common questions
- Where does Glyceria canadensis naturally grow?
- Rattlesnake Grass is native to 21 states across the northeastern, midwestern, and select northwestern regions of North America, including Connecticut, Massachusetts, Michigan, Minnesota, and others.
- What growing conditions does Rattlesnake Grass prefer?
- This native grass thrives in consistently moist to wet soils and tolerates partial sun to full shade conditions, making it well-suited for wetland margins and boggy areas.
- When does Glyceria canadensis bloom?
- Rattlesnake Grass produces its flower spikes during the summer months of June, July, and August.
- Is Rattlesnake Grass toxic to livestock?
- The USDA PLANTS Database does not flag Rattlesnake Grass as toxic to livestock.
- Is Rattlesnake Grass HOA-friendly?
- Rattlesnake Grass 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.
Ready to grow Rattlesnake Grass? Add it to your garden in Pollinator Patch to track it and get season-by-season care guidance.
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