Elodea Common Water Weed

Elodea is a rooted pond weed that grows in the fine sediments and cool waters of ponds. The scientific name is elodea canadensis, but is also known as common waterweed, Canadian elodea, Canadian waterweed, water weed.

Elodea leaves arranged in whorls of 3 going up the plant getting closer together and smaller towards the top. Stems range 2 to 4 feet in length. Leaves are bright green throughout the year. Leaf edges are smooth.

Elodea is a native aquatic plant throughout most of the United States and Canada.

Elodea plant provides habitat for aquatic insects and fish. It is a food source for waterfowl, muskrats and beavers.

Elodea is one of the few pond plants to remain green throughout the year. Because this weed remains active all year, it provides habitat and cover to aquatic organisms year round. This includes winter months when other pond weeds may die back.

Much like other pond plants, large amounts of growth in Elodea is a result of excess nutrients such as nitrogen and phosphorus present in the water. These nutrients can be the result of fertilizers from lawns, pesticides from local fields, etc.

Overgrowth of Elodea can become a nuisance and impair recreational pond activities such as boating, swimming, and fishing. Excess growth can also cause depleted oxygen levels and result in fish kills.

Elodea vs Hydrilla

Elodea leaves have smooth edges whereas hydrilla leaves have toothed edges. Leaves of elodea grow in whorls of 3 versus hydrilla leaves grow in whorls of 4-8 leaves. Hydrilla produces tubers that root deeper in soil and can grow in much deeper water.

Physical forms of control include cutting/raking the Elodea, stocking your pond with Triploid Grass Carp, and drawing down the water in the pond during the winter.

While cutting/ raking the pond may seem to be an immediate solution, Elodea can reproduce at rapid rates through fragmentation and it is very easy to miss small fragments floating in your pond resulting in a reinfestation of Elodea.

Triploid Grass Carp have been proven to be a suitable alternative to raking your pond for Elodea as the pond weed is a major part of their natural diet. However, these fish need to be acquired from a licensed fishery that has approval to sell these fish and as a pond owner you need a permit to stock these fish in your pond.

Since Elodea can grow by fragmentation but it also has a root system, drawing back the water in your pond can be a method to potentially freeze and kill the remainder of the plants. While this method is not always feasible due to the uses of the pond it is a natural method that allows for weed control all the way down to the roots.

Sonar is a systemic aquatic herbicide that comes in granular and liquid form. Like other systemic herbicides Sonar is a slow acting herbicide making it best for ponds or bodies of water with minimal flow. Sonar can be used as an entire pond treatment. Sonar is available in both liquid (Sonar AS and Sonar RTU) and granular forms (Sonar One). This treatment takes approximately 30 days to begin noticing results.

Propeller is an excellent choice for faster acting control of elodea canadensis. This is a contact herbicide.

Harvester is a fast acting diquat based aquatic herbicide meaning that it is a contact herbicide and will not move throughout the plant, the only parts affected will be the parts that directly come in contact with the herbicide. It is important to not over treat your pond as it will cause low oxygen levels which can end with fish kills.