Largeleaf Pondweed

[ Potamogeton amplifolius ]

Largeleaf Pondweed (Potamogeton amplifolius) is notorious for its resistance to herbicide treatments. Found in the upper one-half of the United States.

Largeleaf Pondweed
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Big-leaf pondweed has two leaf types: large, usually wavy-edged underwater leaves which are curved into a banana shape, and oval, leathery floating leaves that grow on or near the water surface. The underwater leaves often decay late in the growing season, making big-leaf pondweed easy to confuse with other floating-leaved pondweeds.

Q. What are the best control options?

Herbicide Application:
Aquathol Super K or Hydrothol 191 granular is a good choice but maximum label rates are recommended. If other plants are present that require control the good news is that improvement is most likely assured with these broad spectrum herbicides. You may want to control a monotypic stand of Largeleaf Pondweed by cutting. See below.

Largeleaf cuts more easily than many aquatic plants and will not regrow the same season. See Water weed cutter.

Q. When is the best time to treat?

Once water temperatures are around sixty degrees or warmer and the plants are viable

Q. How do I actually apply the product(s)?

Granular herbicides can be spread by a small Hand held spreader or can be tossed by a hand scoop.

Q. How often do I need to treat Largeleaf Pondweed?

Controlled Largeleaf will not grow back the same season.