American Pondweed


Ecological Importance

Submerged portions of all aquatic plants provide habitats for many micro and macro invertebrates.


A fast growing and hardy plant species American Pondweed (also known as long leaf pondweed) forms dense mats and block sunlight for submersed vegetation species.

Plant Description:

American Pondweed (Potamogeton nodosus) has submersed and floating oval shaped leaves 4 - 7 inches long and up to 2 inches wide. Leaves are arranged in an alternated pattern on slender stems.

When full maturity is reached, seed heads are seen extending above the water's surface and are brownish to reddish in color.

There are several other similar plants with floating leaves like Illinois, Floating and Waterthread Pondweeds. These plants are common and widespread throughout the United States.

Common Application Questions

Q. What are the best control options?

A. Herbicide Application:
Hydrothol 191 Granular or Aquathol Super K granular are very good control agents.

Q. When is the best time to treat?

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

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

A. 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?

A. Generally, there is little regrowth within the same season. Note that some aquatic species like the Naiad family grow later in the season that may require a mid to later season treatment to achieve season long clear water.

Q. How long before I see results?

A. Generally within two weeks things will be cleared up.


Homeowner Treatment Options
Aquathol K
Aquathol Super K
Hydrothol Granular
Sonar AS
Sonar Q
Sonar RTU
Weedtrine D
*Aquatic Biologists recommends implementing preventative management techniques and physical removal prior to, or in conjunction with treatment.