Photo: TimCC BY 4.0via iNaturalistresized / cropped
Capricorn Eelgrass Plant Care
Zostera capricorni Asch.
Updated · Sources · How we source care data
With long, ribbon-like leaves that can grow up to one meter in length, this seagrass species originates from Australia's coastal waters. Plant collectors are drawn to Zostera capricorni for its unique and elegant appearance, making it a sought-after addition to underwater gardens and aquariums.
Every 7–14 days
Full sun to partial shade
60–75°F
60–80%
At a glance
How do you care for Capricorn Eelgrass?
Water Capricorn Eelgrass 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 60–75°F (16–24°C) and 60–80% humidity. Fertilize it every month during the growing season.
Where Is the Capricorn Eelgrass Native To?
What Is the Capricorn Eelgrass?
Capricorn Eelgrass (Zostera capricorni) belongs to the Zosteraceae family within the Zostera genus. Capricorn Eelgrass is native to the seacoasts of New Guinea, Queensland, New South Wales, Victoria, South Australia, Norfolk Island and the North Island of New Zealand. Capricorn Eelgrass is also known as Eelgrass.
Capricorn Eelgrass displays a submerged aquatic perennial growth habit, reaching up to 3 ft tall with a spread of approximately . Capricorn Eelgrass produces small inconspicuous flowers.
Leaf size: approximately 12 inches.
How Often Should You Water a Capricorn Eelgrass?
Zostera capricorni 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 Capricorn Eelgrass Need?
Capricorn Eelgrass thrives in full sun to partial shade.
Light Requirement
Full sun to partial shade
What Temperature and Humidity Does the Capricorn Eelgrass Prefer?
Zostera capricorni grows best at temperatures of 60–75°F. Capricorn Eelgrass prefers humidity levels of 60–80%. A pebble tray or humidifier helps maintain adequate moisture around the plant.
Temperature
60–75°F
Humidity
60–80%
What Soil Mix Works Best for a Capricorn Eelgrass?
Sandy, muddy or silty substrate in marine or estuarine environments. Good drainage is essential for Capricorn Eelgrass to prevent waterlogging, which leads to root rot and fungal issues.
How Often Should You Fertilize a Capricorn Eelgrass?
Feed Capricorn Eelgrass 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 Capricorn Eelgrass?
Does not require traditional potting, as it is a marine plant. 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 Capricorn Eelgrass?
Capricorn Eelgrass can be propagated through vegetative propagation via rhizomes. Similar propagation techniques also apply to narrowleaf eelgrass plant care, which shares the same genus.
Is the Capricorn Eelgrass Toxic to Pets and Children?
Pet safety not verified
The ASPCA does not list Capricorn Eelgrass, 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 Capricorn Eelgrass?
Capricorn Eelgrass is susceptible to generally not prone to pests. 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 Capricorn Eelgrass Need?
Capricorn Eelgrass grows outdoors in USDA Zone 9b – 12b. It survives winters down to planting zone 9b. Capricorn Eelgrass is native to the seacoasts of New Guinea, Queensland, New South Wales, Victoria, South Australia, Norfolk Island and the North Island of New Zealand. In cooler regions, grow Capricorn Eelgrass as a houseplant or bring it indoors before the first frost.
Hardiness Zone
Zone 9b – 12b
Keep exploring plants
Capricorn Eelgrass 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 Zostera genus — compare its care with other Zostera species on PlantoScan.
Zostera is part of the Zosteraceae plant family — browse all Zosteraceae genera and species.
Capricorn Eelgrass thrives in bright light and direct sun — see other bright-light plants.
More Zostera Species
Other Zostera species in PlantoScan's care catalogue share similar watering, light, and soil preferences:
Sources
- Scientific name & taxonomy: Zostera capricorni Asch., family Zosteraceae (first published in Sitzungsber. Ges. Naturf. Freunde Berlin 1876: 11 (1876)) — World Flora Online record, IPNI name record.
- Pet toxicity: Pet safety not verified: the ASPCA does not list Capricorn Eelgrass, 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: Tim, CC BY 4.0, iNaturalist — original.
- Hardiness zone: USDA Zone 9b – 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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