Control Duckweed

Many people ask how to get rid of duckweed. The following options can be considered for how to control duckweed.

Click here to read more about identifying this plant.

Manual/Mechanical Control:

If you are considering how to remove duckweed, physically seining this plant can be a somewhat effective method of control. However, physical control can be difficult. Duckweed can re-grow from any buds remaining in the water.

Herbicide Control:

There are multiple options for how to kill duckweed that offer great control.

1. Dibrox (for ponds or lakes) – liquid that is diluted with water and sprayed over the plants, fast acting.
2. Spritflo (for ponds with no outflow) – liquid that is poured and spreads throughout the entire body of water, offers extended control.
3. Semera or Flumigard + surfactant (for ponds or lakes) – granules that are dissolved and mixed or liquids that are mixed and diluted with water and sprayed over the plants (early morning is best), fast acting.

When treating duckweed,

• It is important to apply product evenly over all active plant growth; this plant can replicate rapidly from untreated or surviving plants.
• Make sure you have identified the correct plant. Duckweed and watermeal are often confused. Proper identification can help save time, effort, and money.
• Spritflo can be used at the first signs of growth.