Pond Boss Forums AQUATIC VEGETATION Controlling unwanted plants Curly-Leaf Pondweed

Ok. Thank you, Esshup!

Just thought I’d give an update to anyone interested. I did my first attempt at spraying last weekend. Sprayed 2 tank fulls (2 gallon hand sprayer) of a mix of Diquat and cutrinePlus. I think I did 8 ounces of Diquat and about 4 ounces of Cutrine in each tank.

Because I was getting to the spraying late (due to a combination of getting slow response from Neighbors on the pond about being ok with me doing treatments, and due to weather (windy, cold, cloudy days that weren’t good for treatment) the weeds had already gotten pretty thick in some areas and reached the surface fully.

I sprayed those mats along the shore about 1/3 of the pond. I’ve been checking to see how they responded. It appears there was some impact at the very surface, but underneath the weeds still seem to be growing.

I sprayed again this morning, on a different section of the pond, with an increased amount of Diquat (approx 12 oz in a tank) and also with non ionic aquatic Surfectant added. Will monitor and see how this goes and see what I should try next.

From my reading it seems like the issue I’m going to run into is that since the weeds already reached a matted level, it’s going to be difficult to get the spray down deep enough into the water column to really kill them. I saw mention of dragging underwater hoses to describe spray deeper. I don’t really have any capability for that since I’m just using a hand pump sprayer in a canoe…

Anyway, we’ll see how this second spraying goes. Trying to be careful and not accidentally kill too much at once and cause any issues with the fish in the pond. So would rather mess up on the careful side and have the weeds grow more than I’d like, than go overboard and kill fish.

That's the nice thing about Fluridone, just dump the correct amount in the pond and walk away. It kills the weeds over a 30-45 day period. You have to treat the whole pond at once though. The dosage that kills the CLPW won't affect other native plants.

Right, but the problem was, I was trying to not kill all the pond weed, and leave some of it to hopefully consume the nutrients so the algae didn’t get so bad. Not sure that’s gonna work out though.

Also, now that the weeds have grown up, if I did Fluridone now, I’m guessing that would maybe be too much weeds material killed, and may make oxygen levels crash, which I don’t want to happen.

If you have aeration in your pond, I wouldn't worry about killing them all with Fluridone. They die slowly, and with the aeration in there it will help greatly. If you don't kill them all now before they set their turions, I'd hit the pond in late September or October with the fluridone to kill them. That way you won't have a bunch to deal with in the Spring and the colder water holds more O2.

I don't know if you or maybe your HOA would be interested in getting a Jenson Lake Mower? (I used to manufacture it before selling to Elastec, Inc. in 2020.) It would allow you to cut exactly where you want and leave the rest.

From what our customers told us over the years, you want to be sure to mow before the plants form seeds; that way you should see "significant reduction in growth".

The person I'm quoting was managing two lakes. He mounted two Lake Mowers one on each side of his boat, so he could cut 8 feet wide.