Photo: María Regina SilvaCC BY 4.0via iNaturalistresized / cropped
Grass-leaved Yellow-eyed Grass Plant Care
Olsynium biflorum (Thunb.) Goldblatt
Updated · Sources · How we source care data
This plant's slender, grass-like leaves are a vibrant shade of green, complementing the delicate, two-toned flowers. Originating from Chile, Olsynium biflorum is highly sought after by collectors for its unique and striking beauty, making it a prized addition to any garden or collection.
Every 7–10 days
Full sun to partial shade
50–80°F
40–60%
At a glance
How do you care for Grass-leaved Yellow-eyed Grass?
Plant Grass-leaved Yellow-eyed Grass in full sun to partial shade (USDA zones 8a–10b) and water a young shrub every 7–10 days until it is established. It tolerates temperatures of 50–80°F (10–27°C). Fertilize it every 6 months during the growing season. It is reported as toxic to pets, so keep it out of reach of pets.
What Is the Grass-leaved Yellow-eyed Grass?
Grass-leaved Yellow-eyed Grass (Olsynium biflorum) belongs to the Iridaceae family within the Olsynium genus. Grass-leaved Yellow-eyed Grass is native to Argentina and Chile. Grass-leaved Yellow-eyed Grass is also known as Yellow-eyed Grass.
Grass-leaved Yellow-eyed Grass displays a low rosette, clumping growth habit, reaching up to 0.5 ft tall with a spread of approximately 0.5 ft. Grass-leaved Yellow-eyed Grass produces small star-shaped flowers in shades of blue, purple, or white.
Leaf size: approximately 8 inches.
How Often Should You Water a Grass-leaved Yellow-eyed Grass?
Water a young or newly planted Grass-leaved Yellow-eyed Grass every 7–10 days, soaking the whole root zone, until it is established — usually one to two growing seasons. Established shrubs mainly need water during long dry spells. In a container, water whenever the top few centimetres of soil are dry.
Watering Frequency
Every 7–10 days
Until established; then in dry spells
What Light Does the Grass-leaved Yellow-eyed Grass Need?
Grass-leaved Yellow-eyed Grass thrives in full sun to partial shade.
Light Requirement
Full sun to partial shade
What Temperature and Humidity Does the Grass-leaved Yellow-eyed Grass Prefer?
Olsynium biflorum tolerates temperatures of 50–80°F. Grass-leaved Yellow-eyed Grass prefers humidity levels of 40–60%.
Temperature
50–80°F
Humidity
40–60%
What Soil Mix Works Best for a Grass-leaved Yellow-eyed Grass?
Well-draining sandy soil with added organic matter for nutrients. Good drainage is essential for Grass-leaved Yellow-eyed Grass to prevent waterlogging, which leads to root rot and fungal issues.
How Often Should You Fertilize a Grass-leaved Yellow-eyed Grass?
Feed Grass-leaved Yellow-eyed Grass every 6 months during the growing season with a balanced, slow-release fertilizer at the rate on the label. Established shrubs in good soil often need little extra feeding, so let weak growth or pale foliage guide you.
Stop feeding by late summer so new growth can harden before winter.
Fertilizing
Every 6 months
During the growing season
The PlantoScan app can remind you when to water and when to fertilize each plant.
Where Should You Plant a Grass-leaved Yellow-eyed Grass?
Choose a spot with full sun to partial shade and well-draining sandy soil with added organic matter for nutrients. Avoid low spots where water collects after rain.
Grass-leaved Yellow-eyed Grass is suited to USDA Zone 8a – 10b.
Plant container-grown or balled-and-burlapped shrubs in spring or early autumn, setting the root flare at soil level, and water well after planting.
How Far Apart Should You Plant a Grass-leaved Yellow-eyed Grass?
Grass-leaved Yellow-eyed Grass can spread to about 1 ft (0.2 m) and reach about 1 ft (0 m) tall. Space plants about 1 ft (0.2 m) apart so mature crowns don't crowd each other, and plant at least half that distance from buildings, fences and paths.
Planning a row or hedge? Try the plant spacing calculator.
How Do You Prune a Grass-leaved Yellow-eyed Grass?
Prune Grass-leaved Yellow-eyed Grass while it is dormant in late winter: first remove dead, damaged and crossing branches, then thin lightly for shape.
If it flowers in spring, prune right after flowering instead so you don't remove next year's buds. Never take off more than about a quarter of the shrub in one year.
How Do You Care for a Grass-leaved Yellow-eyed Grass in Winter?
Grass-leaved Yellow-eyed Grass is hardy down to USDA zone 8a, so once established it can stay outdoors through winter in that zone and warmer ones.
Water deeply in late autumn before the ground freezes, and spread a 5–8 cm (2–3 in) layer of mulch over the root zone, keeping it away from the trunk.
Young and container-grown shrubs need extra protection: roots in a pot freeze much more easily than roots in the ground.
How Do You Propagate a Grass-leaved Yellow-eyed Grass?
Grass-leaved Yellow-eyed Grass can be propagated through seeds, division of offsets. Similar propagation techniques also apply to rush-leaved yellow-eyed grass plant care, which shares the same genus.
Is the Grass-leaved Yellow-eyed Grass Toxic to Pets and Children?
Toxic (caution)
Reported as toxic in our plant data. Not verified by the ASPCA.
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 Grass-leaved Yellow-eyed Grass?
Grass-leaved Yellow-eyed Grass is susceptible to aphids, thrips, spider mites. 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 Grass-leaved Yellow-eyed Grass Need?
Grass-leaved Yellow-eyed Grass grows outdoors in USDA Zone 8a – 10b. It survives winters down to planting zone 8a. Grass-leaved Yellow-eyed Grass is native to Argentina and Chile.
Hardiness Zone
Zone 8a – 10b
Keep exploring plants
Grass-leaved Yellow-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 Olsynium genus — compare its care with other Olsynium species on PlantoScan.
Olsynium is part of the Iridaceae plant family — browse all Iridaceae genera and species.
Grass-leaved Yellow-eyed Grass thrives in bright light and direct sun — see other bright-light plants.
Related Plant Care Guides
Closely related plants with similar care requirements:
Sources
- Scientific name & taxonomy: Olsynium biflorum (Thunb.) Goldblatt, family Iridaceae (first published in Syst. Bot. 15: 508 (1990)) — World Flora Online record, IPNI name record.
- Pet toxicity: Grass-leaved Yellow-eyed Grass is reported as toxic to pets in our plant data (not verified by the ASPCA), so treat it with caution. Checked against the ASPCA plant list; any other toxicity note on this page comes from PlantoScan's plant database.
- Photo: María Regina Silva, CC BY 4.0, iNaturalist — original.
- Hardiness zone: USDA Zone 8a – 10b, estimated from the plant's typical growing conditions.
- 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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