Image: AI generated
Star Moss Plant Care
Grimmia lawiana J.H.Willis
Updated · Sources · How we source care data
This plant's unique feature is its densely packed, curled, bright green leaves that form a cushion-like appearance. Originally from the mountains of New Zealand, Grimmia lawiana is highly sought after by plant collectors for its unusual texture and compact growth habit, making it a standout addition to any collection.
Every 3–7 days
Medium indirect light
50–75°F
40–70%
At a glance
How do you care for Star Moss?
Water Star Moss every 3–7 days, letting the top layer of soil dry out between waterings, and give it medium indirect light. It prefers temperatures of 50–75°F (10–24°C) and 40–70% humidity. Fertilize it every month during the growing season.
Where Is the Star Moss Native To?
What Is the Star Moss?
Star Moss (Grimmia lawiana) belongs to the Grimmiaceae family within the Grimmia genus. Star Moss is native to East Antarctica. Star Moss is also known as Black Grimmia, Grimmia atrata.
Star Moss displays a low mat-forming growth habit, reaching up to 0.1 ft tall with a spread of approximately 0.5 ft. Star Moss produces tiny inconspicuous flowers.
Leaf size: approximately 0.1 inches.
How Often Should You Water a Star Moss?
Grimmia lawiana requires watering every 3–7 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 3–7 days
Let soil partially dry between waterings
What Light Does the Star Moss Need?
Star Moss thrives in medium indirect light. Avoid placing Star Moss in direct, harsh sunlight for extended periods, as this can scorch the foliage.
Light Requirement
Medium indirect light
What Temperature and Humidity Does the Star Moss Prefer?
Grimmia lawiana grows best at temperatures of 50–75°F. Star Moss prefers humidity levels of 40–70%.
Temperature
50–75°F
Humidity
40–70%
What Soil Mix Works Best for a Star Moss?
Well-draining sandy soil mix with peat moss and perlite. Good drainage is essential for Star Moss to prevent waterlogging, which leads to root rot and fungal issues.
How Often Should You Fertilize a Star Moss?
Feed Star Moss 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 Star Moss?
Repot every 1-2 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 Star Moss?
Star Moss can be propagated through spores, division of clumps. Similar propagation techniques also apply to grey cushion moss plant care, which shares the same genus.
Is the Star Moss Toxic to Pets and Children?
Pet safety not verified
The ASPCA does not list Star Moss, 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 Star Moss?
Star Moss is susceptible to fungus gnats, spider mites, scale insects. 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 Star Moss Need?
Star Moss grows outdoors in USDA Zone 12a. It survives winters down to planting zone 12a. Star Moss is native to East Antarctica. In cooler regions, grow Star Moss as a houseplant or bring it indoors before the first frost.
Hardiness Zone
Zone 12a
Keep exploring plants
Star Moss 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 Grimmia genus — compare its care with other Grimmia species on PlantoScan.
Grimmia is part of the Grimmiaceae plant family — browse all Grimmiaceae genera and species.
Star Moss 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: Grimmia lawiana J.H.Willis, family Grimmiaceae (first published in ANARE Sci. Rep., Ser. B (2), Bot. 82: 148. pl. 41 1966) — World Flora Online record.
- Pet toxicity: Pet safety not verified: the ASPCA does not list Star Moss, 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: AI-generated illustration (labelled on the image).
- 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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