Pond Boss Forums AQUATIC VEGETATION Controlling unwanted plants Pondweed?

I posted about this weed last year. There were just a couple of small patches here and there last year but it has now completely surrounded my pond in a 6' to 8' band. My fish seem to like it but the wife wants it gone. The fish complain less so I need to eliminate it.

1/2 acre pond max 10' depth. No turbidity. Good bloom with about 20" visability.

I stocked two grass carp in '03 and I haven't seen one in a couple of years. They were due to be replaced anyway so I'm going to add two.

I'm planning to rake out as much as I can. It comes out pretty easy. No point in leaving it there to fertilize the next round.

What chemical should I use to kill it? Reward, whitecap? Which is most cost effective for long term?

If my math is correct, I'd need about 15 ounces of whitecap to get 90ppb that's about $300, would take a couple of months to work but would last as long as the ppb stays up. I'm at minimum water shed so I only reach overflow a couple of times per year.

Reward is about $350 for 2.5 gallons. It sounds like it could be used for spot spraying which sounds like that would be easy enough in my situation. I also read that it can be mixed with Cutrine Plus to extend the product and knock out FA in the process (I get a little FA seasonally). Considering the mixing rates, I could probably get 5 treatments out of a 2.5gal jug of Reward, maybe 10 treatments if mixed with Cutrine. Does that sound about right for a 10' band around a 1/2 acre pond and this weed type?

Here's the photos from last year:

Does it produce seeds? From the tangled stems and leaves in the photo it looks like one of the narrow leafed pondweeds (Potomogeton). It is pretty hard to tell what it is from a tangled plant mass in a photo. A better picture of a single stem with leaves and growing tip would/might be more helpful for identificaton.

See this for id help.


http://aquaplant.tamu.edu/database/index.htm

Cody's right. Very hard to tell or identify from tangled mess and decaying matter with it. Best photo sample is single green strand, with stem, leaves and nodes visible on a white background preferably a piece of copy paper 8 1/2 X 11 for size reference also. Shape of leaves, and count of leaves at nodes important.

Bill/Pondfrog, I got a few more photos. Some are on my 6" decking planks and some are on top of the feeder. The plant dried out quickly. Hopefully these will help narrow it down.

Ewest, thanks for the link. I'll check it out soon.

I should also add that Cutrine granualar and Cutrine liquid doesn't seem to affect it.

None of the pictures on ewest's link are an exact match but the baby pondweed is the closest.

The more I look at photos online I'm now leaning toward bushy pondweed. Aren't treatment options are still the same regardless of the particular variety?

As I first posted which is the best option, Whitecap, Reward, or a Reward/Cutrine Plus combination or something else?

I calculated about 20% coverage. A mix of Diquat and Cutrine Plus seems like my best option as I'm not sure what the threshold is for how much of an algae bloom will negatively affect it's perfomance and I do have a small amount of FA mixed in. Due to the flouridone's 6-12 week kill time, it's probably a bit late in the year to get full value out of the product.

I will rake out as much vegetation as I can to further reduce DO issues and nutrient recycling. I'm going to add 2 grass carp too and hopefully they will keep up with re-growth.

I'm considering leaving the weeds on 1/4 of the pond bank near the spawning area (opposite of the swimming area) for fry refuge. I'm not sure if this is a good idea because based on this year's growth a patch of weeds this size will certainly try to spread to other areas but I've read that grass carp prefer new growth as opposed to old.

Any thoughts?

You seem to have a handle on it. I like the Diquat Cutrine combo. Also raking it out to avoid crash problems. And not treating the entire pond this season. Yes, I'm seeing bushy pondweed/naiad also, nice photos. Keep your %'s in specs, partial treat, rake, wait a couple of weeks, repeat. Maybe get 50% first time, 40% second treatment. Leave some for cover for fry, and maybe plan to replace it with better alternative next season after winter, with Spring emergence. Way late in the season for Fluridone. Get dead material or live material out of pond. Soon as it starts losing green coloration is best time for me. Hopefully you will have some nice after photos. A+ for homework and planning. I think grass carp will help a lot with keeping it down Next season.

A lot of that stuff that you leave untreated will die down over the winter and sprout up again. The GC will help take care of it then. If you are going to put GC in the pond, I'd do it this year so they are already in place when the plants start growing next year.

Thanks for the support. I'll post results.

Ryan, I know you said that you're going to replace some grass carp but are your tilapia eating any of it?

I didn't get any tilapia this year. I never had pondweed when I had tilapia though but I don't think they are effective at eliminating it. I did have grasscarp which I haven't seen for two years. GC supposedly like pondweed. I feel that GC and tilapia compliment each other on what they eat. I'm not sure if my GC went out my overflow pipe or died. The owner of a fishfarm told me this weekend that Cutrine plus kills them...the same guy also told me that Reward kills FA and that I should stock 8 GC and they will take care of the FA. He said I probably killed my GC with Cutrine. I was a bit surprised because I have only used about 1 gallon per treatment a few times per year beginning in 2004, and one of those years I didn't use any and another year I only did 1 treatment. I think I've used maybe 14 gallons of Cutrine Plus since the pond was built.

I spent about 4 hours on Friday night raking most of it out. I found lots of interesting creatures: Dragonfly larva at different stages, tadpoles, bluegill and bass minnows, about a dozen mussels and a few "bugs" and worms I didn't reconize. I was happy to find there were no snails or leaches.

I ended up with about a 3' wide 1' tall windrow around the pond. After it dried overnight I mowed over it with my lawn mower a few times. I do not recommend this as now my yard and mower both stink pretty bad.

Saturday morning, everything had settled so I hit most of the border with a mix of Cutrine and Reward and a couple of ounces of Aquashade to make it easier to see where I was spraying. I also mixed up a batch for my cattails and hit a few small patches of crabgrass growing in the rocks. By Sunday, the pondweed was brown and the cattails and grass were bleached. Very fast acting.

I got the latest issue of PB on Thursday but didn't take time to open until Sunday...too bad because Bob had me covered in one of the articles.

I shut of my automatic feeder but threw out a few pellets by hand just to see how the fish would respond yesterday evening. The BG fed but the LMB, HSB, and CC did not. Could this be because all the critters that were hiding in the pondweed are now exposed for easy pickings?

Also, about 10 of the larger gizzard shad were going crazy foraging in the areas the pondweed was raked from.

The Reward/Cutrine mix does well on pondweed...it should give you pretty good results. As far as what the fishfarm guy was telling you...cutrine killing grass carp and Reward killing filamentous algae...I don't think so. I spray ponds and do fish work for a living, and in a lot of the residential ponds, we have to keep them completely free of filamentous algae. Believe me, I have probably put more than 14 gallons of Cutrine in some of them in one summer ...and they still have plenty of grass carp in em. Maybe in his case with trying to control algae in recirculating tanks or something, Cutrine could cause issues. But, if most of your carp are gone, my guess would be they went out an overflow or something like that. I also pretty much have the Reward label memorized, and it says in there something to the affect of: it should only be used for partial control of filamentous algae...for full control mix with an approved algaecide

I agree with you that the tilapia and carp compliment each other...carp do well with submersed stuff and tilapia do well with algae control.

GShad were likely eating all the planktonic critters you stirred up.