Photo: Zihao WangCC BY 4.0via iNaturalistresized / cropped
Duckweed Plant Care
Lemna perpusilla Torr.
Updated · Sources · How we source care data
Lemna perpusilla, also known as the "small duckweed," is a tiny floating plant with oval-shaped, bright green leaves that measure only about 1-3 millimeters in size. It thrives in slow-moving or stagnant water bodies like ponds and lakes, making it a popular choice for aquariums and water gardens.
Every 3–7 days
Full sun to partial shade
60–80°F
50–80%
At a glance
How do you care for Duckweed?
Water Duckweed 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 50–80% humidity. Fertilize it every 2 months during the growing season.
Where Is the Duckweed Native To?
What Is the Duckweed?
Duckweed (Lemna perpusilla) belongs to the Araceae family within the Lemna genus. Duckweed is native to the central and eastern United States, and Quebec in Canada, and has been introduced to various locations around the world. Duckweed is also known as Water Lentil.
Duckweed displays a floating aquatic plant growth habit, reaching up to tall with a spread of approximately . Duckweed produces tiny inconspicuous flowers.
Leaf size: approximately 1 inches.
How Often Should You Water a Duckweed?
Lemna perpusilla 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 Duckweed Need?
Duckweed thrives in full sun to partial shade.
Light Requirement
Full sun to partial shade
What Temperature and Humidity Does the Duckweed Prefer?
Lemna perpusilla grows best at temperatures of 60–80°F. Duckweed prefers humidity levels of 50–80%. A pebble tray or humidifier helps maintain adequate moisture around the plant.
Temperature
60–80°F
Humidity
50–80%
What Soil Mix Works Best for a Duckweed?
Nutrient-rich aquatic soil. Good drainage is essential for Duckweed to prevent waterlogging, which leads to root rot and fungal issues.
How Often Should You Fertilize a Duckweed?
Feed Duckweed every 2 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 2 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 Duckweed?
No need for traditional potting, grows 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 Duckweed?
Duckweed can be propagated through division, daughter plants. Similar propagation techniques also apply to duckweed plant care, which shares the same genus.
Is the Duckweed Toxic to Pets and Children?
Pet safety not verified
The ASPCA does not list Duckweed, 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 Duckweed?
Duckweed is susceptible to algae, aquatic 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 Duckweed Need?
Duckweed grows outdoors in USDA Zone 4a – 11b. It survives winters down to planting zone 4a. Duckweed is native to the central and eastern United States, and Quebec in Canada, and has been introduced to various locations around the world.
Hardiness Zone
Zone 4a – 11b
Keep exploring plants
Duckweed 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 Lemna genus — compare its care with other Lemna species on PlantoScan.
Lemna is part of the Araceae plant family — browse all Araceae genera and species.
Duckweed 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: Lemna perpusilla Torr., family Araceae (first published in Fl. New York 1: 245 (1843)) — World Flora Online record, IPNI name record.
- Pet toxicity: Pet safety not verified: the ASPCA does not list Duckweed, 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: Zihao Wang, CC BY 4.0, iNaturalist — original.
- Hardiness zone: USDA Zone 4a – 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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