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Duckweed Seeds and Live Starter Cultures

Duckweed rarely sets seed. Sellers ship live plants as starter cultures instead.

Updated Oct 28, 2026. Edited by: Ilyass Ben Hakim.

Where to buy

Aquarium shops, pond suppliers and science supply companies sell live duckweed. Hobby sellers ship cups of plants by mail.

Professional insight

Aquarists buy duckweed as a live culture, never as seed. Species and cleanliness matter most.

Confirm Lemna minor versus giant duckweed, Spirodela.
Ask if the culture is snail and pest free.
Order early in the week to avoid weekend transit.
Rinse and quarantine before adding to a tank.

Check the label

Species named, such as Lemna minor.
Live plants, not seed packets.
Plant count or cup size stated.
Grown indoors or outdoors.
Pest, snail and algae free claim.
Live arrival policy and shipping speed.
Seller can ship legally to your state or country.

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Duckweed plant facts

Common species: Lemna minor
Spreads by: Budding new fronds; Flowers and seeds are rare.
Habit: Free floating

Setup tips

1Float the cup in the tank to match temperature.
2Rinse plants in dechlorinated water.
3Spread them on still water with good light.
4Scoop out extra fronds every week.
5Bag and bin surplus plants; do not flush them.

Common questions

Why are duckweed seeds not sold?: The plant rarely flowers. It multiplies by budding, so live plants are easier.
Can duckweed take over a tank?: Yes. It can block light and gas exchange unless thinned.
Can I eat duckweed?: Only food grade duckweed from a safe source. Do not eat pond or tank plants.