We have been fighting a losing battle w/water primrose all summer. We've been removing it manually, but I think we've just managed to spread it even more. Time to get the chemicals. Is it too late in the year to do it now, or should I wait for warmer temps? I know many products are more effective w/warmer temps than with cooling ones, but I know nothing about fighting aquatic weeds. I've also got phragmites, which I also need to eradicate.
