Photo: Owen StricklandCC BY 4.0via iNaturalistresized / cropped
Green-keeled Cotton Grass Plant Care
Eriophorum viridicarinatum Fernald
Updated · Sources · How we source care data
This plant is easily recognized by its vivid green leaves that have distinctive carmine-red edges. Originating from the wetlands of North America, Eriophorum viridicarinatum is highly sought after by plant collectors for its unique coloration and ability to thrive in boggy conditions.
Every 2–4 days
Full sun to part shade
50–75°F
60–80%
At a glance
How do you care for Green-keeled Cotton Grass?
Water Green-keeled Cotton Grass every 2–4 days, letting the top layer of soil dry out between waterings, and give it full sun to part shade. It prefers temperatures of 50–75°F (10–24°C) and 60–80% humidity. Fertilize it every month during the growing season.
Where Is the Green-keeled Cotton Grass Native To?
What Is the Green-keeled Cotton Grass?
Green-keeled Cotton Grass (Eriophorum viridicarinatum) belongs to the Cyperaceae family within the Eriophorum genus. Green-keeled Cotton Grass is native to Canada and the United States. Green-keeled Cotton Grass is also known as Green Keel Cotton Grass.
Green-keeled Cotton Grass displays a grass-like perennial growth habit, reaching up to 3 ft tall with a spread of approximately 1 ft. Green-keeled Cotton Grass produces small, brown spikelets.
Leaf size: approximately 12 inches.
How Often Should You Water a Green-keeled Cotton Grass?
Eriophorum viridicarinatum requires watering every 2–4 days. Allow the top layer of soil to dry between waterings to prevent root rot. Reduce watering frequency during winter when growth slows.
Watering Frequency
Every 2–4 days
Let soil partially dry between waterings
What Light Does the Green-keeled Cotton Grass Need?
Green-keeled Cotton Grass thrives in full sun to part shade.
Light Requirement
Full sun to part shade
What Temperature and Humidity Does the Green-keeled Cotton Grass Prefer?
Eriophorum viridicarinatum grows best at temperatures of 50–75°F. Green-keeled Cotton Grass prefers humidity levels of 60–80%. A pebble tray or humidifier helps maintain adequate moisture around the plant.
Temperature
50–75°F
Humidity
60–80%
What Soil Mix Works Best for a Green-keeled Cotton Grass?
Moist, acidic peat or boggy soil. Good drainage is essential for Green-keeled Cotton Grass to prevent waterlogging, which leads to root rot and fungal issues.
How Often Should You Fertilize a Green-keeled Cotton Grass?
Feed Green-keeled Cotton Grass every month during the growing season (spring and summer) with a balanced fertilizer diluted to the strength on the label.
Pause feeding in autumn and winter, when growth slows, and never fertilize dry soil — water first.
Fertilizing
Every month
During the growing season
The PlantoScan app can remind you when to water and when to fertilize each plant.
How Do You Repot a Green-keeled Cotton Grass?
Divide clumps every 3-5 years. Choose a pot one size larger than the current container, and ensure it has drainage holes to allow excess water to escape.
How Do You Propagate a Green-keeled Cotton Grass?
Green-keeled Cotton Grass can be propagated through division, seeds. Similar propagation techniques also apply to virginia cotton grass plant care, which shares the same genus.
Is the Green-keeled Cotton Grass Toxic to Pets and Children?
Pet safety not verified
The ASPCA does not list Green-keeled Cotton Grass, so we can't confirm whether it is safe for cats and dogs. Keep pets from chewing it as a precaution.
This is a general caution, not veterinary or medical advice. If your pet ate a plant, contact your vet or animal poison control.
See all plants toxic to cats and plants toxic to dogs.
What Pests and Diseases Affect the Green-keeled Cotton Grass?
Green-keeled Cotton Grass is susceptible to generally pest-free. Inspect the foliage regularly, especially along leaf undersides and stems. Treat infestations promptly with insecticidal soap or neem oil to prevent spread.
Yellow leaves, brown tips or drooping? See common plant problems and how to fix them.
What USDA Hardiness Zone Does the Green-keeled Cotton Grass Need?
Green-keeled Cotton Grass grows outdoors in USDA Zone 12a – 6b. It survives winters down to planting zone 12a. Green-keeled Cotton Grass is native to Canada and the United States. In cooler regions, grow Green-keeled Cotton Grass as a houseplant or bring it indoors before the first frost.
Hardiness Zone
Zone 12a – 6b
Keep exploring plants
Green-keeled Cotton Grass is one of many species covered in the complete plant care and identification guide, which groups plants by genus, attribute, and popularity.
It belongs to the Eriophorum genus — compare its care with other Eriophorum species on PlantoScan.
Eriophorum is part of the Cyperaceae plant family — browse all Cyperaceae genera and species.
Green-keeled Cotton Grass thrives in bright light and direct sun — see other bright-light plants.
More Eriophorum Species
Other Eriophorum species in PlantoScan's care catalogue share similar watering, light, and soil preferences:
Sources
- Scientific name & taxonomy: Eriophorum viridicarinatum Fernald, family Cyperaceae (first published in Rhodora 7: 89 (1905)) — World Flora Online record, IPNI name record.
- Pet toxicity: Pet safety not verified: the ASPCA does not list Green-keeled Cotton Grass, so we can't confirm whether it is safe for cats and dogs. Checked against the ASPCA plant list; any other toxicity note on this page comes from PlantoScan's plant database.
- Photo: Owen Strickland, CC BY 4.0, iNaturalist — original.
- Hardiness zone: USDA Zone 12a – 6b, calculated from the plant's minimum temperature.
- Care values(watering, light, temperature, humidity, soil, fertilizing): PlantoScan's plant database, filtered by automatic plausibility checks — values that fail them are hidden. How we source and check plant data.
Spotted a mistake? Email info@upvision.media with the page link — we check and correct reported errors.
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