There are aquatic versions of glyco (roundup).

From Aquaplant
http://aquaplant.tamu.edu/plant-identification/alphabetical-index/white-water-lily/

http://aquaplant.tamu.edu/plant-identifi...can-water-lily/
Rodeo, Aquamaster, Eraser AQ, Touchdown Pro, and AquaNeat are liquid glyphosate formulations and have been effective on white water lily. These are broad spectrum, systemic herbicide. Systemic herbicides are absorbed and move within the plant to the site of action. Systemic herbicides tend to act more slowly than contact herbicides. An aquatically registered surfactant (see the label) will have to be added to the Rodeo solution for good results.


Last edited by ewest; 01/28/11 10:23 AM.