When does Glyceria canadensis bloom?

Glyceria canadensis typically flowers from June through August, producing its drooping, nodding seed heads during these summer months.

What growing conditions does rattlesnake grass need?

This grass does best in consistently wet to saturated soil and part shade, conditions similar to those found in marshes, wet meadows, and bog margins.

Is Glyceria canadensis a good choice for a rain garden or wet meadow planting?

Yes, because it tolerates high moisture and part shade, it fits well along pond edges, in bog gardens, and in low spots that stay damp through the growing season.

Does rattlesnake grass stay green year round?

No, it is a deciduous perennial grass that dies back to the ground each year and regrows from its base in spring.

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.

Rattlesnake Grass

Name: Pollinator Patch
Author: Pollinator Patch

Glyceria canadensis

Last reviewed: August 2026

Rattlesnake grass, Glyceria canadensis, is a wetland grass that flowers from June through August and thrives in consistently wet, part shaded sites like marshes and bog edges.

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

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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

When does Glyceria canadensis bloom?: Glyceria canadensis typically flowers from June through August, producing its drooping, nodding seed heads during these summer months.
What growing conditions does rattlesnake grass need?: This grass does best in consistently wet to saturated soil and part shade, conditions similar to those found in marshes, wet meadows, and bog margins.
Is Glyceria canadensis a good choice for a rain garden or wet meadow planting?: Yes, because it tolerates high moisture and part shade, it fits well along pond edges, in bog gardens, and in low spots that stay damp through the growing season.
Does rattlesnake grass stay green year round?: No, it is a deciduous perennial grass that dies back to the ground each year and regrows from its base in spring.
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.

If something looks wrong

Common plant problems, and what to check first

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