Controlling Duckweed in a Heron-Prone Pond Without Chemicals

Natural Controls

• Fish: Goldfish, koi, grass carp eat duckweed.
• Ducks/Turtles: Love it.
• Surface Agitation: Duckweed hates moving water. Add a fountain, waterfall, or horizontal pump outlet.
• Competing Floaters: Water hyacinth, water lettuce, salvinia (tropicals) outcompete it.

Heron Connection

Herons hunt by sight. Thick duckweed hides fish. Your previous heron problem may have been solved by the duckweed! Fish eat it, herons can't see fish.

No Herbicides

Any chemical killing duckweed harms other plants and the ecosystem.