Control Pondweed

While there are many varieties of Potamogeton (pondweeds), control for nearly all of them is the same. The following options can be considered for how to control pondweeds.

Click here to read more about identifying these plants.

Manual/Mechanical Control:

If you are considering how to remove pondweeds, physically raking or seining the plants out can be a somewhat effective method of control. However, physical control can be difficult. Pondweeds can re-grow from any rhizomes or seeds remaining in the water. The level of control will vary slightly with each type of pondweed.

Herbicide Control:

There are a few options for how to kill pondweeds that offer great or some control.

1. Spritflo (for ponds with no outflow) – liquid that is poured and spreads throughout the entire body of water, offers extended control.
2. Hydrothol (for lakes) – granules that are broadcast over where the plants are.
3. Dibrox (for ponds or lakes) – liquid that is diluted with water and sprayed over the plants, fast acting. This will give some control.
4. Cattail and Water Lily Control (Imox + surfactant) (for ponds or lakes) – liquids that are mixed and diluted with water and sprayed directly on the plants and in the area where they are. Much higher rate needed than for emergent plants. Will offer some control.

Treatment Tips:

When treating pondweeds,

• Spritflo can be used at the first signs of growth.
• With other herbicides, treat when the plants are established and actively growing.
• Imox will be absorbed through the leaves that are floating on the water. Check the label or call for guidance on rates based on the depth of the water where the pondweeds are growing. At the higher rates, Imox can also be absorbed through submersed leaves and stems.