Thank you both for the good info!
I’m in central Indiana. East of Indianapolis.
My suspicion as to why the curly leaf comes back each year despite the treatments is that the neighborhood has several ponds, and there are drainage pipes that I believe run between them to some extent. I’m guessing one or more of the inflow pipes reintroduce the weeds from other ponds.
Also possible, the treatment company doesn’t want to fully kill the weeds because they want to keep getting the $900 a year for that treatment. 😂
