Thread-leaved Yellow-eyed Grass Plant Care

Thread-leaved Yellow-eyed Grass (Olsynium filifolium) belongs to the Iridaceae family within the Olsynium genus. Thread-leaved Yellow-eyed Grass is native to the Falkland Islands.

Thread-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. Thread-leaved Yellow-eyed Grass produces small star-shaped flowers in shades of blue, purple, or white.

Leaf size: approximately 8 inches.

Water a young or newly planted Thread-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.

Thread-leaved Yellow-eyed Grass thrives in full sun to partial shade.

Olsynium filifolium tolerates temperatures of 50–80°F. Thread-leaved Yellow-eyed Grass prefers humidity levels of 40–60%.

Well-draining sandy soil with added organic matter for nutrients. Good drainage is essential for Thread-leaved Yellow-eyed Grass to prevent waterlogging, which leads to root rot and fungal issues.

Feed Thread-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.

The PlantoScan app can remind you when to water and when to fertilize each plant.

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.

Thread-leaved Yellow-eyed Grass is suited to USDA Zone 12a.

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.

Thread-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.

Prune Thread-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.

Thread-leaved Yellow-eyed Grass is frost-tender (hardy to USDA zone 12). In colder areas grow it in a container and move it to a bright, frost-free place before the first frost.

Thread-leaved Yellow-eyed Grass can be propagated through seeds, division of offsets. Similar propagation techniques also apply to grass-leaved yellow-eyed grass plant care, which shares the same genus.

See all plants toxic to cats and plants toxic to dogs.

Thread-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.

Thread-leaved Yellow-eyed Grass grows outdoors in USDA Zone 12a. It survives winters down to planting zone 12a. Thread-leaved Yellow-eyed Grass is native to the Falkland Islands. In cooler regions, grow Thread-leaved Yellow-eyed Grass as a houseplant or bring it indoors before the first frost.