Photo: LjažCC BY 4.0via iNaturalistresized / cropped
Opposite-leaved Pondweed Plant Care
Groenlandia densa Fourr.
Updated · Sources · How we source care data
This aquatic plant's small, bright green, needle-like leaves are its most distinctive feature. Hailing from North America, Groenlandia densa is prized by plant collectors for its ability to create dense mats in ponds and aquariums, providing both aesthetic appeal and a habitat for small aquatic creatures.
Every 7–14 days
Full sun to partial shade
65–75°F
60–80%
At a glance
How do you care for Opposite-leaved Pondweed?
Water Opposite-leaved Pondweed 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 65–75°F (18–24°C) and 60–80% humidity. Fertilize it every month during the growing season.
Where Is the Opposite-leaved Pondweed Native To?
- Albania
- Algeria
- Angola
- Armenia
- Austria
- Azerbaijan
- Bahrain
- Belarus
- Belgium
- Benin
- Bosnia and Herzegovina
- Botswana
- Bulgaria
- Burkina Faso
- Burundi
- Cameroon
- Cape Verde
- Central African Republic
- Chad
- Côte d'Ivoire
- Croatia
- Cyprus
- Czechia
- Denmark
- Djibouti
- DR Congo
- Egypt
- Equatorial Guinea
- Eritrea
- Estonia
- Eswatini
- Ethiopia
- Finland
- France
- Gabon
- Georgia
- Germany
- Ghana
- Greece
- Guinea
- Guinea-Bissau
- Hungary
- Iceland
- Iran
- Iraq
- Ireland
- Israel
- Italy
- Jordan
- Kenya
- Kuwait
- Latvia
- Lebanon
- Lesotho
- Liberia
- Libya
- Lithuania
- Luxembourg
- Madagascar
- Malawi
- Mali
- Malta
- Mauritania
- Moldova
- Montenegro
- Morocco
- Mozambique
- Namibia
- Niger
- Nigeria
- North Macedonia
- Norway
- Oman
- Palestine
- Poland
- Portugal
- Qatar
- Republic of the Congo
- Romania
- Russia
- Rwanda
- Sao Tome and Principe
- Saudi Arabia
- Senegal
- Serbia
- Sierra Leone
- Slovakia
- Slovenia
- Somalia
- South Africa
- South Sudan
- Spain
- Sudan
- Sweden
- Switzerland
- Syria
- Tanzania
- The Gambia
- The Netherlands
- Togo
- Tunisia
- Türkiye
- UAE
- Uganda
- Ukraine
- United Kingdom
- Yemen
- Zambia
- Zimbabwe
What Is the Opposite-leaved Pondweed?
Opposite-leaved Pondweed (Groenlandia densa) belongs to the Potamogetonaceae family within the Groenlandia genus. Opposite-leaved Pondweed is native to much of Europe, western Asia and Maghreb in Africa. Opposite-leaved Pondweed is also known as Dense Pondweed.
Opposite-leaved Pondweed displays an aquatic perennial herb growth habit, reaching up to tall with a spread of approximately 1 ft. Opposite-leaved Pondweed produces small inconspicuous flowers on spikes above water.
Leaf size: approximately 2 inches.
How Often Should You Water a Opposite-leaved Pondweed?
Groenlandia densa 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 Opposite-leaved Pondweed Need?
Opposite-leaved Pondweed thrives in full sun to partial shade.
Light Requirement
Full sun to partial shade
What Temperature and Humidity Does the Opposite-leaved Pondweed Prefer?
Groenlandia densa grows best at temperatures of 65–75°F. Opposite-leaved Pondweed prefers humidity levels of 60–80%. A pebble tray or humidifier helps maintain adequate moisture around the plant.
Temperature
65–75°F
Humidity
60–80%
What Soil Mix Works Best for a Opposite-leaved Pondweed?
Rich, loamy soil with good organic content and consistent moisture. Good drainage is essential for Opposite-leaved Pondweed to prevent waterlogging, which leads to root rot and fungal issues.
How Often Should You Fertilize a Opposite-leaved Pondweed?
Feed Opposite-leaved Pondweed 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 Opposite-leaved Pondweed?
Does not require traditional potting, grows in aquatic environments. 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 Opposite-leaved Pondweed?
Opposite-leaved Pondweed can be propagated through division, seeds.
Is the Opposite-leaved Pondweed Toxic to Pets and Children?
Pet safety not verified
The ASPCA does not list Opposite-leaved Pondweed, 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 Opposite-leaved Pondweed?
Opposite-leaved Pondweed is susceptible to algae, aquatic weeds. 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 Opposite-leaved Pondweed Need?
Opposite-leaved Pondweed grows outdoors in USDA Zone 5a – 10b. It survives winters down to planting zone 5a. Opposite-leaved Pondweed is native to much of Europe, western Asia and Maghreb in Africa.
Hardiness Zone
Zone 5a – 10b
Keep exploring plants
Opposite-leaved Pondweed 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 Groenlandia genus — compare its care with other Groenlandia species on PlantoScan.
Groenlandia is part of the Potamogetonaceae plant family — browse all Potamogetonaceae genera and species.
Opposite-leaved Pondweed 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: Groenlandia densa Fourr., family Potamogetonaceae (first published in Ann. Soc. Linn. Lyon , n.s., 17: 169 (1869)) — World Flora Online record, IPNI name record.
- Pet toxicity: Pet safety not verified: the ASPCA does not list Opposite-leaved Pondweed, 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: Ljaž, CC BY 4.0, iNaturalist — original.
- Hardiness zone: USDA Zone 5a – 10b, 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.
Identify Plants Like the
Opposite-leaved Pondweed Instantly
Scan any plant with your phone camera and get instant ID, care tips, water and fertilizer reminders, and health checks — all in one app.
Free
to download
iOS & Android
platforms
Light & dark
mode
100,000+
species