CONTROLLING WATER LILIES IN POND
Had a few questions this weekend about controlling water lilies in a pond. These are considered non native and evasive in nature. Recommendation is basically using Glyphosate herbicide labelled for use near and in water. Aquamaster and Aqua Neat would be the 2 products I would recommend. It can be sprayed directly on the lily plant so you can control some and leave a few to enjoy.
Great website with more fundamental information: State of Washington