Photo: Valentin KosterinCC BY 4.0via iNaturalistresized / cropped
Watermeal Plant Care
Wolffia arrhiza (L.) Horkel ex Wimm.
Updated · Sources · How we source care data
This tiny plant floats on water and is often mistaken for algae due to its minute size and lack of roots. Originating from tropical regions around the world, Wolffia arrhiza's minuscule scale and unique appearance make it highly sought after by plant collectors looking to add a rare and intriguing specimen to their collection.
Every 3–7 days
Full sun to partial shade
60–80°F
50–70%
At a glance
How do you care for Watermeal?
Water Watermeal every 3–7 days, letting the top layer of soil dry out between waterings, and give it full sun to partial shade. It prefers temperatures of 60–80°F (16–27°C) and 50–70% humidity. Fertilize it every month during the growing season.
Where Is the Watermeal Native To?
- Albania
- Algeria
- Angola
- Austria
- 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
- Germany
- Ghana
- Greece
- Guinea
- Guinea-Bissau
- Hungary
- Iceland
- Ireland
- Italy
- Kenya
- Latvia
- Lesotho
- Liberia
- Libya
- Lithuania
- Luxembourg
- Madagascar
- Malawi
- Mali
- Malta
- Mauritania
- Moldova
- Montenegro
- Morocco
- Mozambique
- Namibia
- Niger
- Nigeria
- North Macedonia
- Norway
- Poland
- Portugal
- Republic of the Congo
- Romania
- Russia
- Rwanda
- Sao Tome and Principe
- Senegal
- Serbia
- Sierra Leone
- Slovakia
- Slovenia
- Somalia
- South Africa
- South Sudan
- Spain
- Sudan
- Sweden
- Switzerland
- Tanzania
- The Gambia
- The Netherlands
- Togo
- Tunisia
- Uganda
- Ukraine
- United Kingdom
- Zambia
- Zimbabwe
What Is the Watermeal?
Watermeal (Wolffia arrhiza) belongs to the Araceae family within the Wolffia genus. Watermeal is native to Europe, Africa, and parts of Asia, it has also become naturalised in various other regions around the globe. Watermeal is also known as Duckweed.
Watermeal displays a floating aquatic plant growth habit, reaching up to tall with a spread of approximately . Watermeal produces tiny inconspicuous flowers.
How Often Should You Water a Watermeal?
Wolffia arrhiza 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 Watermeal Need?
Watermeal thrives in full sun to partial shade.
Light Requirement
Full sun to partial shade
What Temperature and Humidity Does the Watermeal Prefer?
Wolffia arrhiza grows best at temperatures of 60–80°F. Watermeal prefers humidity levels of 50–70%. A pebble tray or humidifier helps maintain adequate moisture around the plant.
Temperature
60–80°F
Humidity
50–70%
What Soil Mix Works Best for a Watermeal?
Nutrient-rich aquatic environment. Good drainage is essential for Watermeal to prevent waterlogging, which leads to root rot and fungal issues.
How Often Should You Fertilize a Watermeal?
Feed Watermeal 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 Watermeal?
Does not require traditional potting, thrives in water. 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 Watermeal?
Watermeal can be propagated through division, fragmentation. Similar propagation techniques also apply to watermeal plant care, which shares the same genus.
Is the Watermeal Toxic to Pets and Children?
Pet safety not verified
The ASPCA does not list Watermeal, 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 Watermeal?
Watermeal is susceptible to not typically susceptible 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 Watermeal Need?
Watermeal grows outdoors in USDA Zone 8a – 11b. It survives winters down to planting zone 8a. Watermeal is native to Europe, Africa, and parts of Asia, it has also become naturalised in various other regions around the globe.
Hardiness Zone
Zone 8a – 11b
Keep exploring plants
Watermeal 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 Wolffia genus — compare its care with other Wolffia species on PlantoScan.
Wolffia is part of the Araceae plant family — browse all Araceae genera and species.
Watermeal 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: Wolffia arrhiza (L.) Horkel ex Wimm., family Araceae (first published in Fl. Schles. , ed. 3: 140 (1857)) — World Flora Online record, IPNI name record.
- Pet toxicity: Pet safety not verified: the ASPCA does not list Watermeal, 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: Valentin Kosterin, CC BY 4.0, iNaturalist — original.
- Hardiness zone: USDA Zone 8a – 11b, 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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