Calamagrostis expansa Plant Care
Calamagrostis expansa Hitchc.
Updated · Sources · How we source care data
Greeneochloa expansa is a species of grass in the family Poaceae known by the common name Maui reedgrass. It is native to Hawaii, where it is known only from Maui and the island of Hawaiʻi.
Every 7–14 days
Full sun to partial shade
50–80°F
40–70%
At a glance
How do you care for Calamagrostis expansa?
Water Calamagrostis expansa every 7–14 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 8 months during the growing season.
Where Is the Calamagrostis expansa Native To?
What Is the Calamagrostis expansa?
Calamagrostis expansa (Calamagrostis expansa) belongs to the Poaceae family within the Calamagrostis genus. Calamagrostis expansa is native to Hawaii.
Calamagrostis expansa displays a clump-forming grass growth habit, reaching up to 3 ft tall with a spread of approximately 2 ft. Calamagrostis expansa produces feathery flower heads in summer.
Leaf size: approximately 12 inches.
How Often Should You Water a Calamagrostis expansa?
Calamagrostis expansa 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 Calamagrostis expansa Need?
Calamagrostis expansa thrives in full sun to partial shade.
Light Requirement
Full sun to partial shade
What Temperature and Humidity Does the Calamagrostis expansa Prefer?
Calamagrostis expansa grows best at temperatures of 50–80°F. Calamagrostis expansa prefers humidity levels of 40–70%.
Temperature
50–80°F
Humidity
40–70%
What Soil Mix Works Best for a Calamagrostis expansa?
Well-draining loamy soil with good organic content. Good drainage is essential for Calamagrostis expansa to prevent waterlogging, which leads to root rot and fungal issues.
How Often Should You Fertilize a Calamagrostis expansa?
Feed Calamagrostis expansa every 8 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 8 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 Calamagrostis expansa?
Divide clumps 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 Calamagrostis expansa?
Calamagrostis expansa can be propagated through division, seed sowing. Similar propagation techniques also apply to feather reed grass plant care, which shares the same genus.
Is the Calamagrostis expansa Toxic to Pets and Children?
Pet safety not verified
The ASPCA does not list Calamagrostis expansa, 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 Calamagrostis expansa?
Calamagrostis expansa is susceptible to aphids, grasshoppers, 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 Calamagrostis expansa Need?
Calamagrostis expansa grows outdoors in USDA Zone 12a. It survives winters down to planting zone 12a. Calamagrostis expansa is native to Hawaii. In cooler regions, grow Calamagrostis expansa as a houseplant or bring it indoors before the first frost.
Hardiness Zone
Zone 12a
Keep exploring plants
Calamagrostis expansa 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 Calamagrostis genus — compare its care with other Calamagrostis species on PlantoScan.
Calamagrostis is part of the Poaceae plant family — browse all Poaceae genera and species.
Calamagrostis expansa thrives in bright light and direct sun — see other bright-light plants.
More Calamagrostis Species
Other Calamagrostis species in PlantoScan's care catalogue share similar watering, light, and soil preferences:
Sources
- Scientific name & taxonomy: Calamagrostis expansa Hitchc., family Poaceae (first published in Mem. Bernice Pauahi Bishop Mus. 8: 149 (1922)) — World Flora Online record, IPNI name record.
- Pet toxicity: Pet safety not verified: the ASPCA does not list Calamagrostis expansa, 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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