None that I know of, but I haven't researched it. I wonder if you cut off the lilies below the water surface, spray a contact herbicide on the watermeal, I wonder if the lilies would skate by unscathed?

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3/4 to 1 1/4 ac pond LMB, SMB, PS, BG, RES, CC, YP, Bardello BG, (RBT & Blue Tilapia - seasonal).