Pond Boss Forums AQUATIC VEGETATION Controlling unwanted plants American Pondweed

I have treated some areas of American Pondweed around my pond with Weedtrine.

The leaves of the treated plants turned brown within a few hours (untreated areas seem largely unaffected).

Is there a certain time period that I should wait before I try to manually remove dead or dying plants? ie will it get down into the roots if I wait a while?

I don't want to leave all of that stuff to rot and decompose if I don't need to, but "IF" they can be killed at the roots, then I'll wait.

Derek, I had the exact same experience in my pond but tried raking them out a couple of days later, which did NOT work as they were still pretty firmly rooted. I haven't had a chance to try again since then, but will be interested in reading the feedback you get from others who may have insight offer.

I don't mind if I can't pull the roots. If I can pull the top half out, that's 3/4 of the organic material removed.

My bigger concern is whether or not the plant is likely to grow back again. Does the herbicide need time to get down into the root system and kill the plant? In which case I can give it time (though it's actually been 4 days now...but good to know for future reference). Or will it just kill off the surface portions anyway, in which case, I should have simply done a manual removal and simply expect them back a couple times per year.

This is really the only aquatic vegetation that has been somewhat aggressive. At first it was one or two specific spots in the pond, then this year, it took hold all the way around. I didn't remove any last year until after seeds were established, so it's largely my own fault. FA and other algae have been easy to ward off, and I'm keeping an eye on cattails, but they've haven't exploded or anything.

There are several questions I have.

First how big is your pond. What size area was treated with weedtrine and how much weedtrine did you use for given area. If american pondweed browned out several hours after initial application it sound like you had a chemical burn instead of getting herbicide to react with plant material.

Weedtrine is a diquat that works on pondweed and is really effective if mixed with copper i.e. cutrine plus.

Either way if you start raking pondweed out before it dies off it will reestablish itself because it has a good strong root system. If herbicide does not get down to root system then it may be better to reapply weedtrine or something else to get effective management of American Pondweed.

Pond is 1.5 acreas. I treated a little more than 1/3 of the perimeter. I used 1/2 gallon of weedtrine, mixed with 1.5 gallons of water and sprayed it liberally onto the floating leaves near shore.

I didn't mix in any copper, but I had treated the algae in the pond about 7-10 days earlier, using about 10 lbs of copper sulphate, spread around most of the perimeter. This took care of the algae, and seemed to really increase water clarity for a while...from about 1 ft up to 4.5 feet.

Get about 8 Grass Carp. I have a 1 acre pond and I had Pondweed around 100 percent of it out about 15 to 20 feet from shore. This year I have about 10 percent and pond looks much, much better. Plus you don't have to pull anything as the GC will eat the Pondweed root and all. They love that stuff! Top on their buffet list!

Good Luck,

I like American Pondweed. But I rarely if ever have a problem with it. Where it has little or no competition in a pond I have seen it get a little thick. To me it is close to a beneficial plant. I don't like using herbicides unless it is a last resort, and I rarely copper. Sinking algae with copper just feeds the next bloom. Stuff hand pulls fairly easy.

Yes, grass carp would be perfect, but they aren't allowed in Michigan, unfortunately.

Of all the weeds I could have, this seems pretty reasonable. It makes nice fish cover which is why I've left a fair bit of it in key places. But this year, it has really taken off. It's getting heavier in our swimming areas, and it also makes it a little difficult to fish from the shore unless I clear parts out. I just need to find a compromise.

Too much of a good thing syndrome is very understandable. I would hand pull it from undesirable areas. It has a fairly strong stem or stalk and usually I can get it roots and all out. I'm actually introducing that and smartweed into a pond or two here and there as the alternative weeds are a complete disaster. I prefer growth on surface, open water under it. But with pondweed if you have the time and are physically able, I would selective harvest it out of unwanted areas.

Derek PF knows his vegetation - give heed!

Remember, something will use your excess nutrient load in the pond. Beneficial plants like pondweed are far better than the alternative filamentous algae or invasives.

I totally understand the pondweed presently an access challenge - here's a tip from someone with plenty of pondweed:

Try using light jigs [1/64 oz and up] and plastics or gulp. They can be fished right through the pondweed most times without any foul ups. My most successful presentation for all my species is a 1/32 oz jighead and 2" twister or tube.

In terms of keeping areas clear, my main concern is that I am maintaining a fairly large swimming area. My family swims several times per week in the summer, and more importantly, I host a couple large "events" with over 100 people at my home and many swimming. For that reason, I'd like to keep that large areas looking "clean" for my guests. The other small area (not a big deal at all) is near my feeder, so that all the fish food can make into the water and not get hung up on the 10-12 foot wide mat of pondweed.

I don't mind manually removing the weeds, but I have a couple concerns if I am relying strictly on manual removal:
1. Will it grow back repeatedly during the same year?
2. Will it grow back thicker each successive year?
3a. I have absolutely no time to pull pond weeds until summer (mid June). I live on 12 acres, and I rarely get to mow my lawn more than once April - June.
3b. I don't have much luck removing with the rake. It works best when I get in the water and spend a few hours doing it by hand. I don't mind this, but I can't stand cool water...gotta wait for 80 degree water or I'm freezing. By then, stuff is pretty well established.

If I need to rely on manual removal as my primary tool,then I'll live with that, but in situations where I need to take back control and decide to go with a herbicide, I'm still not sure of the answer to my first question...how long should I wait after application before plants are "dead" and can be removed with growing back from the roots.

I'm not sure if it's the clay on my pond bottom, but I am never able to pull up roots from this kind of pond weed. I just try to grab it as low as I can and pull up as much as I can.

Thanks for all the tips...and I will experiment with your fishing tips as well. I am admittedly a terrible fisherman, so every bit helps, especially as it relates to my pond setup.

I would not want to swim among the American Pondweed either. Yuck. Yes, if you don't like cooler water that is a problem, because best time to attack it is Spring emergence. It must be rooting in a pretty dense bottom like clay instead of muck. Another problem. If you are using a systemic it should kills the entire plant all the way down to the roots. Depending on how much active ingrediant sticks to the leaves is how long it takes. But you should be back to square one pulling out the dead material instead of live, which I why I just pull it out live if I can.

I lake mower curly leaf pondweed, and rake it out. I also clear out swimming beaches and surface areas. Most plants I mow or pull in the Summer do not grow back very well. If I get at the root structure they don't at all. I'm even pulling up coontal which has no root structure but anchors in the muck and mowing it. Even the material I got back a few months ago did not grow back to much of any degree. I think you need to clear out the swimming holes and eradicate there completely. You have to kill the roots and clear it out of the pond, everywhere you don't want it. It normally is not a fast spreader, in fact, it is usually slower than many species. Wheter you hand pull or spot treat with herbicide, get the plants out and reduce the nutrients. That is probably the source of many of your problems.

Once killed, the pondweed shouldn't grow back if sunlight can't get to the bottom of the pond.

For that busy of a schedule, I'd vote for herbacide.

Naturally as soon as I post how American Pondweed is not that bad I lose a real large lmb into the worst infested pond I have. Naturally I don't have a photo of it but another biggie I caught there earlier. C and R of course, I'll get it loaded down with Omaha's help tomorrow, long shift today. My baitfish has deep teeth marks about a 1/4" apart. Only big lunker lmb have teeth like that. I just could not turn it to keep it out.

Derek

If you can't use GC then I would suggest at about the Mid way through April or May whenever your area starts warming up into the 50's or 60's I would start to use Aquashade. I used a gallon of this on my 1 acre pond and wow did it make a difference. It set my weeds back a good month or so and I only used it once. A gallon is about 50 bucks, but after that you can maintain your pond with about 14 ounces an acre per month. So basically your could get by with about 3 gallons if your pond is 1.5 acres. It will turn your pond pretty dark at first and you won't get an algea bloom more than likely but it seems to work wonders on the weeds and I don't know for sure but I would imagine it's more safe then any herbicide your putting in your pond. The dye is perfectly safe for animals, people and birds. Just another thing you may want to try for next year. One thing you need to rememb er though is with the lack of weeds may come a lack of DO in your pond. Especially if you do not have any aeration going on in your pond.

I do aerate full-time, but I am already wondering if there are DO issues. My other post: http://www.pondboss.com/forums/ubbthreads.php?ubb=showflat&Number=228323#Post228323

For whatever it's worth, this is the first spring that I haven't added any dye. There is no inlet or outlet to my pond, and I still had a strong blue tint from last year's application.

Satellite Photo from May shows my pond as bright light blue. My neighbor to the east is shown in black, and the larger natural body to the west is also dark.