Mountain Blue-eyed Grass Plant Care
Sisyrinchium montanum Greene
Updated · Sources · How we source care data
Sisyrinchium montanum, the blue-eyed-grass, American blue-eyed-grass, or strict blue-eyed grass, is a grass-like species of plant from the genus Sisyrinchium, native to northern North America from Newfoundland west to easternmost Alaska, and south to Pennsylvania in the east, and to New Mexico in the Rocky Mountains. It has also been introduced to parts of France, likely during the First World War.
Every 7–10 days
Full sun to partial shade
50–80°F
40–70%
At a glance
How do you care for Mountain Blue-eyed Grass?
Water Mountain Blue-eyed Grass every 7–10 days, letting the top layer of soil dry out between waterings, and give it full sun to partial shade. It prefers temperatures of 50–80°F (10–27°C) and 40–70% humidity. Fertilize it every 6 months during the growing season.
Where Is the Mountain Blue-eyed Grass Native To?
What Is the Mountain Blue-eyed Grass?
Mountain Blue-eyed Grass (Sisyrinchium montanum) belongs to the Iridaceae family within the Sisyrinchium genus. Mountain Blue-eyed Grass is native to northern North America from Newfoundland west to easternmost Alaska, and south to Pennsylvania in the east, and to New Mexico in the Rocky Mountains. Mountain Blue-eyed Grass is also known as Blue-eyed Grass.
Mountain Blue-eyed Grass displays a clumping perennial growth habit, reaching up to 1 ft tall with a spread of approximately 1 ft. Mountain Blue-eyed Grass produces small, star-shaped flowers in shades of blue, purple, or yellow.
Leaf size: approximately 6 inches.
How Often Should You Water a Mountain Blue-eyed Grass?
Sisyrinchium montanum requires watering every 7–10 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 7–10 days
Let soil partially dry between waterings
What Light Does the Mountain Blue-eyed Grass Need?
Mountain Blue-eyed Grass thrives in full sun to partial shade.
Light Requirement
Full sun to partial shade
What Temperature and Humidity Does the Mountain Blue-eyed Grass Prefer?
Sisyrinchium montanum grows best at temperatures of 50–80°F. Mountain Blue-eyed Grass prefers humidity levels of 40–70%.
Temperature
50–80°F
Humidity
40–70%
What Soil Mix Works Best for a Mountain Blue-eyed Grass?
Well-draining sandy loam with added organic matter. Good drainage is essential for Mountain Blue-eyed Grass to prevent waterlogging, which leads to root rot and fungal issues.
How Often Should You Fertilize a Mountain Blue-eyed Grass?
Feed Mountain Blue-eyed Grass every 6 months 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 6 months
During the growing season
The PlantoScan app can remind you when to water and when to fertilize each plant.
How Do You Repot a Mountain Blue-eyed Grass?
Divide and repot every 2-3 years in early spring. 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 Mountain Blue-eyed Grass?
Mountain Blue-eyed Grass can be propagated through division of rhizomes, seeds. Similar propagation techniques also apply to bermuda blue-eyed grass plant care, which shares the same genus.
Is the Mountain Blue-eyed Grass Toxic to Pets and Children?
Pet safety not verified
The ASPCA does not list Mountain Blue-eyed 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 Mountain Blue-eyed Grass?
Mountain Blue-eyed Grass is susceptible to aphids, spider mites, thrips. 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 Mountain Blue-eyed Grass Need?
Mountain Blue-eyed Grass grows outdoors in USDA Zone 12a. It survives winters down to planting zone 12a. Mountain Blue-eyed Grass is native to northern North America from Newfoundland west to easternmost Alaska, and south to Pennsylvania in the east, and to New Mexico in the Rocky Mountains. In cooler regions, grow Mountain Blue-eyed Grass as a houseplant or bring it indoors before the first frost.
Hardiness Zone
Zone 12a
Keep exploring plants
Mountain Blue-eyed 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 Sisyrinchium genus — compare its care with other Sisyrinchium species on PlantoScan.
Sisyrinchium is part of the Iridaceae plant family — browse all Iridaceae genera and species.
Mountain Blue-eyed Grass thrives in bright light and direct sun — see other bright-light plants.
More Sisyrinchium Species
Other Sisyrinchium species in PlantoScan's care catalogue share similar watering, light, and soil preferences:
Sources
- Scientific name & taxonomy: Sisyrinchium montanum Greene, family Iridaceae (first published in Pittonia 4: 33 (1899)) — World Flora Online record, IPNI name record.
- Pet toxicity: Pet safety not verified: the ASPCA does not list Mountain Blue-eyed 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.
- Hardiness zone: USDA Zone 12a, 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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