Elodea submerged pond weed
Elodea is a rooted pond weed that grows in the fine sediments and cool waters of ponds. It has leaves arranged in whorls of 3 going up the plant getting closer together and smaller towards the top. The scientific name is elodea canadensis, but is also known as common waterweed.
Elodea is one of the few pond plants to remain green throughout the year providing habitat and cover to aquatic organisms year round. This includes winter months when other pond weeds may die back.
Is Elodea good or bad for my pond?
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.
How to get rid of Elodea
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.
Best treatment to kill Elodea
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.
Tsunami DQ 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.