Aquatic Weeds

Plant identification is vital before an aquatic weed management strategy can be developed. If you cannot identify the plant to species, at least select a major grouping based on plant characteristics. View the complete K-State Research and Extension publication on Aquatic Plants and Their Control for more information. When the plant has been identified, chemical control options are possible.

Grass carp can control some aquatic plant species. They prefer some plants to others, grow very quickly and consume lots of vegetation. They should be stocked at the rate of 20 fish per acre when about 50 percent of the pond is covered with aquatic vegetation. When there is only a narrow belt of vegetation around the edge, 10 fish per acre may be enough. Stock with grass carp at least 10-12 inches long to avoid predation by the existing fish in the pond. Grass carp can sometimes eat too much of the vegetation and cause planktonic algae to increase which reduces water clarity. Grass carp may live for 50 years and weigh over 50 pounds. Management of grass carp may be necessary to avoid them eating most of the desirable vegetation and reducing fish productivity. Purchase grass carp through aquaculture producers associated with the Kansas Aquaculture Association.

A great source of information on aquatic plants and how to identify and manage them is Aquaplant from Texas A&M University.