What Are the Treatments for Water Hyacinth?

Water hyacinth (Eichhornia crassipes) is a prolific and invasive aquatic plant. Originating in the Amazon basin, water hyacinth was introduced to the rest of the world as an ornamental pond plant because of its bright, lavender-colored flowers. In a short period of time, water hyacinth has managed to overtake water systems, cause disease, and reduce fish populations. There are several treatments to rid waterways of water hyacinth. Each option has its own benefits and disadvantages.

Biological Treatment

• Biological control is the use of natural enemies to control or reduce pests. Moths, fungi and a variety of weevils have been identified as predators of water hyacinth. Biological control has proved to be very successful in Africa. The weed weevil was introduced to Africa’s Lake Victoria, resulting in 90 percent eradication of the water hyacinth population.

Physical Treatment

• Physically removing water hyacinth is the best short-term solution. Unfortunately, this treatment is the most expensive. Equipment such as cranes, booms, mowers or weed harvesters have to be rented or bought to complete the task. These machines can easily remove the water hyacinth from the water. Once the water hyacinth is removed, it must be put in a truck to be transported for disposal. This method is also labor and time intensive. It will take many hours operating the machines, placing the plants into trucks and transporting them to disposal locations.

  Another physical treatment that is currently being researched is removing the nutrients from the water. It is speculated that reducing the nutrients that water hyacinth thrives on will reduce its proliferation. This treatment is more of a preventative measure than a method of eradication, but will hopefully control water hyacinth’s severe over-population.

Chemical Treatment

• Applying herbicides to eradicate water hyacinth is the most effective method. The common herbicides used are 2,4-d, Diquat, and Glysophate. The drawback, like with any chemical usage, is the long-term effect on the environment. Herbicides can kill non-targeted plants and pollute the water.

  A certified technician should apply the herbicides. The chemicals can be applied from the ground for small infestations or from the air for larger infestations. It may take several applications before you will notice a gradual browning and decline of the water hyacinth.