Photo: scallionsCC BY 4.0via iNaturalistresized / cropped
Flatleaf yelloweyed grass Plant Care
Xyris complanata R.Br.
Updated · Sources · How we source care data
With its distinctive bright yellow star-shaped flowers, Xyris complanata originates from wetlands in Southeastern United States. Plant collectors are drawn to its unique appearance and ability to thrive in boggy soil, making it a standout addition to any water garden.
Every 3–5 days
Full sun to partial shade
60–85°F
50–70%
At a glance
How do you care for Flatleaf yelloweyed grass?
Water Flatleaf yelloweyed grass every 3–5 days, letting the top layer of soil dry out between waterings, and give it full sun to partial shade. It prefers temperatures of 60–85°F (16–29°C) and 50–70% humidity. Fertilize it every 6 months during the growing season.
Where Is the Flatleaf yelloweyed grass Native To?
What Is the Flatleaf yelloweyed grass?
Flatleaf yelloweyed grass (Xyris complanata) belongs to the Xyridaceae family within the Xyris genus. Flatleaf yelloweyed grass is native to southern China, India, Sri Lanka, Thailand, Cambodia, Laos, Vietnam, Malaysia, Indonesia, the Philippines, New Guinea and Australia.
Flatleaf yelloweyed grass displays a grass-like perennial growth habit, reaching up to 1 ft tall with a spread of approximately 0.5 ft. Flatleaf yelloweyed grass produces small yellow flowers on tall spikes.
Leaf size: approximately 12 inches.
How Often Should You Water a Flatleaf yelloweyed grass?
Xyris complanata requires watering every 3–5 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 3–5 days
Let soil partially dry between waterings
What Light Does the Flatleaf yelloweyed grass Need?
Flatleaf yelloweyed grass thrives in full sun to partial shade.
Light Requirement
Full sun to partial shade
What Temperature and Humidity Does the Flatleaf yelloweyed grass Prefer?
Xyris complanata grows best at temperatures of 60–85°F. Flatleaf yelloweyed grass prefers humidity levels of 50–70%. A pebble tray or humidifier helps maintain adequate moisture around the plant.
Temperature
60–85°F
Humidity
50–70%
What Soil Mix Works Best for a Flatleaf yelloweyed grass?
Sandy, acidic soil with good drainage. Good drainage is essential for Flatleaf yelloweyed grass to prevent waterlogging, which leads to root rot and fungal issues.
How Often Should You Fertilize a Flatleaf yelloweyed grass?
Feed Flatleaf yelloweyed 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 Flatleaf yelloweyed grass?
Repot every 1-2 years in 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 Flatleaf yelloweyed grass?
Flatleaf yelloweyed grass can be propagated through division, seeds. Similar propagation techniques also apply to ambiguous yellow-eyed grass plant care, which shares the same genus.
Is the Flatleaf yelloweyed grass Toxic to Pets and Children?
Pet safety not verified
The ASPCA does not list Flatleaf yelloweyed 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 Flatleaf yelloweyed grass?
Flatleaf yelloweyed grass is susceptible to aphids, 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 Flatleaf yelloweyed grass Need?
Flatleaf yelloweyed grass grows outdoors in USDA Zone 10a – 12b. It survives winters down to planting zone 10a. Flatleaf yelloweyed grass is native to southern China, India, Sri Lanka, Thailand, Cambodia, Laos, Vietnam, Malaysia, Indonesia, the Philippines, New Guinea and Australia. In cooler regions, grow Flatleaf yelloweyed grass as a houseplant or bring it indoors before the first frost.
Hardiness Zone
Zone 10a – 12b
Keep exploring plants
Flatleaf yelloweyed 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 Xyris genus — compare its care with other Xyris species on PlantoScan.
Xyris is part of the Xyridaceae plant family — browse all Xyridaceae genera and species.
Flatleaf yelloweyed grass thrives in bright light and direct sun — see other bright-light plants.
More Xyris Species
Other Xyris species in PlantoScan's care catalogue share similar watering, light, and soil preferences:
Sources
- Scientific name & taxonomy: Xyris complanata R.Br., family Xyridaceae (first published in Prodr. Fl. Nov. Holland. : 256 (1810)) — World Flora Online record, IPNI name record.
- Pet toxicity: Pet safety not verified: the ASPCA does not list Flatleaf yelloweyed 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: scallions, CC BY 4.0, iNaturalist — original.
- Hardiness zone: USDA Zone 10a – 12b, 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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