Photo: no rights reservedCC0 1.0via iNaturalist
Knotty Spear Grass Plant Care
Austrostipa nodosa (S.T.Blake) S.W.L.Jacobs & J.Everett
Updated · Sources · How we source care data
This striking grass species is easily identified by its nodding, feathery flower heads that sway gracefully in the wind. Originating from Australia, Austrostipa nodosa is sought after by plant collectors for its unique appearance and ability to add texture and movement to gardens and landscapes.
Every 7–14 days
Full sun
50–90°F
30–70%
At a glance
How do you care for Knotty Spear Grass?
Water Knotty Spear Grass every 7–14 days, letting the top layer of soil dry out between waterings, and give it full sun. It prefers temperatures of 50–90°F (10–32°C) and 30–70% humidity. Fertilize it every month during the growing season.
Where Is the Knotty Spear Grass Native To?
What Is the Knotty Spear Grass?
Knotty Spear Grass (Austrostipa nodosa) belongs to the Poaceae family within the Austrostipa genus. Knotty Spear Grass is native to Australia and New Zealand.
Knotty Spear Grass displays a tall, clumping grass growth habit, reaching up to 5 ft tall with a spread of approximately 2 ft. Knotty Spear Grass produces inconspicuous flowers on tall stalks.
Leaf size: approximately 12 inches.
How Often Should You Water a Knotty Spear Grass?
Austrostipa nodosa requires watering every 7–14 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 7–14 days
Let soil partially dry between waterings
What Light Does the Knotty Spear Grass Need?
Knotty Spear Grass thrives in full sun.
Light Requirement
Full sun
What Temperature and Humidity Does the Knotty Spear Grass Prefer?
Austrostipa nodosa grows best at temperatures of 50–90°F. Knotty Spear Grass prefers humidity levels of 30–70%.
Temperature
50–90°F
Humidity
30–70%
What Soil Mix Works Best for a Knotty Spear Grass?
Well-draining sandy soil with good aeration. Good drainage is essential for Knotty Spear Grass to prevent waterlogging, which leads to root rot and fungal issues.
How Often Should You Fertilize a Knotty Spear Grass?
Feed Knotty Spear 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 Knotty Spear Grass?
Divide clumps every 2-3 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 Knotty Spear Grass?
Knotty Spear Grass can be propagated through seeds. Similar propagation techniques also apply to tussock grass plant care, which shares the same genus.
Is the Knotty Spear Grass Toxic to Pets and Children?
Pet safety not verified
The ASPCA does not list Knotty Spear 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 Knotty Spear Grass?
Knotty Spear Grass is susceptible to grasshoppers, aphids. 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 Knotty Spear Grass Need?
Knotty Spear Grass grows outdoors in USDA Zone 9a – 11a. It survives winters down to planting zone 9a. Knotty Spear Grass is native to Australia and New Zealand. In cooler regions, grow Knotty Spear Grass as a houseplant or bring it indoors before the first frost.
Hardiness Zone
Zone 9a – 11a
Keep exploring plants
Knotty Spear 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 Austrostipa genus — compare its care with other Austrostipa species on PlantoScan.
Austrostipa is part of the Poaceae plant family — browse all Poaceae genera and species.
Knotty Spear Grass thrives in bright light and direct sun — see other bright-light plants.
More Austrostipa Species
Other Austrostipa species in PlantoScan's care catalogue share similar watering, light, and soil preferences:
Sources
- Scientific name & taxonomy: Austrostipa nodosa (S.T.Blake) S.W.L.Jacobs & J.Everett, family Poaceae (first published in Telopea 6: 587 (1996)) — World Flora Online record, IPNI name record.
- Pet toxicity: Pet safety not verified: the ASPCA does not list Knotty Spear 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: Public domain, CC0 1.0, iNaturalist — original.
- Hardiness zone: USDA Zone 9a – 11a, 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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