Pond Boss Forums AQUATIC VEGETATION Controlling unwanted plants Curly-leafed pond weed

I made a whoops when I added a pond lily last fall, some curly-leafed pond weed seed must have rode in on the media and have sprouted all around it. I have been manually pulling it around the lily, but am afraid it will be a loosing battle. It is tough as heck to snorkel in there and get to the base of the plants without harming the lily.

I only have a 20sq foot area I need to eradicate this stuff from, but it is intertwined with a beautiful dark-red lily I would like to keep which is a prolific bloomer.

What are my options? Should I nuke the lily and surrounding plants from orbit? Will I have a chance of eradicating it manually? Will grass carp eat it and leave the lily alone? I doubt it.

Seeing how much plant control costs makes me think the nuke from orbit may be my best option to stop it before it gets out of control.

Also we swim in the pond, so I would prefer something safe and ecologically sound.

Sidenote: Lots of baby cattails coming up all around the pond. It has been only a few months, so I can only assume there were fuzzies in the air from nearby swamps. I am planning on letting them grow in select areas of the pond but maintaining control.

Oh, and Mr. Yellow flag is going bye-bye.

3 years ago a buddy said the exact same words about the cattails. Guess what? Last year he nuked 'em all and he's pulling up everyone that he sees now.

Can you remove the lily, rinse off the roots, nuke the curly leaf and replant the lily?

Curly Leaf pond weed is really a curious plant. Last year was the first time I had this plant and I had read how it comes on fast in the spring and then dies back for some reason. This year it looked like it was going to take over the pond and so I put in 6 GC a month ago. Not enough time for them to control it, but then it died back or whatever it does by 3/4% it seems. I like this plant for my minnows as it has an airy loose look in the water that the minnows freely swim through, adds to the oxygen in the water and so far has contributed to the no growth of FA,,,, so far.

I wish I could get the lily up, but when I planted it, it weighed upwards of 80-90 pounds. Not to mention I planted it where there is a sluff in the intention of using the lily roots to hold things together. So far THAT plan worked as the lily really has one hell of a root system!

After reading it seems like manual control may be best as if I stay on top of it to where it cannot form pods or seeds, the plant will be done in the hot weather and there will be less of them to deal with next year.

As far as cat tails, you may be right, but there are areas of shoreline where I have constant water seepage/springs into the pond where I cannot access with equipment. Weed-eating is even risky there since the soil is not stable enough to risk it (full of gas!). The thought is better cattails than poplar or willow trees.

Ah, the pleasure of having wacky springs full of natural gas. Somewhere nearby is a badly-plugged natural gas well that is leaking gas into the aquafier and is getting into all of our groundwater.

Look into Arrowhead. That will create root to hold things together too.

Check out Sonar A.S. They treated a local lake with it in a low dose to control EWM and Curly Leaf. Around this time of the year is when the Curly Leaf dies back naturally.

My experience matches John. Curly-leaf pondweed got into one of the local oxbox lakes. It always is gone by mid-July, so it is an unusual short-lived plant. So, that is actually nice, but watch out for the oxygen debt as it decays. Another tidbit is that it propogates from seeds! Each crop grows from seeds each spring. Again, unusual.

Curly-leaf can spread fast as you are seeing. It spreads by seeds as Dr Dave says and also by winter buds called turions that form on the stems. The seasonal die back noted by John and Dr Dave is due to the plant being a cool water plant that flowers, produces seeds, and turions early season, then most plants die back during the warm water season of maybe late Jun, Jul-Aug-earlySep depending on location and water color.

In NY in late June IMO you are too late to stop the formation of seeds & turions for next seasons crop unless you have kept all plants pruned close to the sediment. You have to cut or prune it close to the bottom early in spring before it reaches the surface to stop formation of seeds and turions. This helps slow the spread.

Since your colonization is supposedly still small you could spot treat the area with Aquathol Super K or Hydrothol 191 - both granular herbicides that work well on smaller spot treatments of curly-leaf. Smallest containers I think are 10 lb pails and a little pricey. Hydrothol in higher concentrations and large applications can be toxic to fish so be careful if you use that one. But if you use it just around your red lily it should be okay. Do not over dose; read the label and instructions. You will see effects in several days on killing the curly-leaf. You probably will not eradicate all the plants with one treatment. You will probably need to re-treat again mid-fall(early Oct) when turions sprout and are 2"-6" tall or treat early next spring well before it reaches the surface. Neither herbicide should kill your water lily.

One good thing about curly-leaf is it provides good short plant cover and habitat during cold water of winter, very early spring when about all other plants are dying and collapsing. Another good thing is it uses lots of nutrients in cold water thus competing against and reducing the amount of cold water algae.

http://www.midwestaquacare.com/product-labels/Aquathol-Super-K-label.pdf

http://www.aquaticbiologists.com/Labels/Hydrothol191Gran.pdf

Great info, as always, from Bill!!

A local guy has used Aquathol Super K on spot treating his curly leaf with water lilies present. He said it did not harm the lilies and got good control for the curly-leaf. The pond has a few years of turion production so he has to treat about every spring to stay ahead of the growths.

Hmm, all great info!

Our water didn't get real warm until about 2 weeks ago, so I mostly was able to keep the plant down to a minimum. Probably missed a few, but got 98% of it it down to the mud. The remaining plant material all blew into one corner of the pond today, the turions and all so I was able to remove it effectively. It seems the plants were just starting to form turions.

Local observation of ponds shows they almost all have clpw, and almost all universally it is not a real problem other than making fishing a bit more challenging.

As a side-note we went fishing in the Avon DEC pond this morning. Lots of sunnies and small bass, but one GIANT tiger muskie cruising around looking for snacks.

Please refer to these (newest) labels:
http://www.cdms.net/LDat/ld2AE009.pdf (Super K)
http://www.cdms.net/LDat/ld8UG004.pdf (Hydrothol granular)

Incognito, eh?
Welcome!

Kelly what is your experience with spot treating curly leaf?

Actually, I rarely encounter curly leaf pondweed in TX. It is present, but hasn't posed much of a problem to my knowledge.

Well, after all of my trying, it is a loosing battle :-(. This stuff LOVES my conditions. It is sending runners over 20' long across the surface and turions all over the place now. At this rate I will have a chocked out pond even though the nutrients are very low. Swimming through it showed me just tons of minnows hiding in it though, so it makes great cover. I may have to nuke from orbit this fall.

Reward - diquat killed curly leaf quickly in my pond in June. And it worked when the water had visibilities of about 16". I suggest killing it early before it reaches the surface. If you kill it in the late fall expect to see some dormant turions sprout in early spring and a 2nd treatment would be necesssary.

What is the safety of this stuff for swimming? A lot of scary warnings on the label for handling.

BTW I have over 6' of easy visibility and plenty of sunlight down at 12+ feet. Easy to snorkel down there and play "search for the lost tool". Probably the clearest pond one could hope for, that pleasant blue-green color full of life. FHM don't grow so fast though.

-Mark

Reward degrades very quickly which is the big benefit to using this herbicide.

Well, I haven't done any treatment since I have recently added my YP, WE, and BC to the pond and want to have more than 0 minnows left in the spring.

I wanted to update everyone how CLPW grows in our cool northern waters with hard, alkaline PH 8.5 or so... the stuff just doesn't quit! Water temps at 41 near the surface, sun out full bore, and oxygen bubbles streaming up from the plants still! That is amazing photosynthesis in my book. There is a patch of CLPW that is already about 30x30 that must of spread from a turon earlier this summer. The plants grow FAST even in November, and never quit in the summer.

I do see gobs of minnows swimming in the plants, and they seem to have done an amazing job of clarifying the water. I can now see down a deceptive 8-9 feet now fairly well, making the pond look oddly shallow. Cool to see schools of FHM swimming in different size classes at different depths.

It does appear to be a great plant for cover, but lousy for fishing and swimming. I will be getting some grass carp this spring to keep it somewhat tame, so I am guessing 2 of them for now just to keep the stuff from taking over the whole pond. I want some plants for a healthy pond, just don't want a green blob.

Now if we can only get some precip. 0.75" of rain for the entire month of November is unheard of in these parts.

The way I use my pond for nature, the Curly Leaf Pond Weed is about the perfect plant for my minnow and tadpoles. It gets somewhat thick and then backs off to nearly nothing and the pond does bubble a lot with oxygen rising to the surface that you can see in bright sun reflection off the water. The plant leaves are spread and loose in the water so fish can swim through them as opposed to many other plants that seem chocked together under water.

The last three years I have allowed my cattails to do what they want and boy have they taken off. So be careful with the cattails. The cattails harbor ducks and Redwing black birds in particular and with the brown dead stocks this time of year the tadpoles actually boil the water in them when I walk up close.

Still getting over my food/cleaning/cooking coma... family badgering me to get off the computer, but I refuse to join in Black Friday.

The only reason I am keeping the cattails it to prevent erosion problems on the downhill side of the pond. The soil there is so nutrient poor thanks to over-farming I could barely get grass to grow this year. Even alfalfa is having a rough go of it :-(. More dirt is showing than plants. The cattails, while rather pathetic, are the only things holding the soil in-place right now near the max water line, and that side of things is steep. I don't want wash-outs on that hill or in the pond.

I really don't want to fertilize this hill as I am certain that if I do it will finally rain enough to wash it all into the pond. Then I will have some real problems, even though I prefer organic fertilizers.

Going to try some clover next spring, alfalfa doesn't seem to be doing what I need.

As far as the CLPW, it seems to be an excellent plant for the ecology of the pond. I am just curious when it will finally die back, if at all in my pond.

-Mark

Curly-leaf typically dies back after it goes to seed and the turions form. CLPW die back for me in NW Ohio is in June before July4. If the pond has blue dye its whole life cycle is delayed. Sprouting of the turions occurs in Aug-Sept.

Greetings:

IMO.... I would not be overly concerned about Curlyleaf pondweed (CLP a.k.a P. crispus) in your pond. Although there are many management approaches to controlling this exotic plant, I believe the best approach is to assist "Mother Nature" through selective plant control. Encouraging dense growths of bottom forms of advanced algae such as Chara and Nitella help "crowd out" dense growths of CLP. Aquathol K is extremely safe and effective on CLP. The ecological advantage of using Aquathol K is that it totally biodegrades into Hydrogen, Carbon, and Oxygen (no swimming restriction). Using a small amount of aquatic polymer with a penetrant and injecting the chemical into the early growing "plant bed" helps in reducing chemical usage. In order to reduce future growth.....I would most definitely treat this plant BEFORE the production of turions.....which is in late April to early May in Ohio. (Water temps 50-60 degrees).

I do believe that some levels of CLP growth is beneficial for a pond or lake considering that it provides early cover for many lakes that have little or no structure. Your lily will flourish just fine with this management approach. Avoid the use of copper, 2,4D, fluridone, and simazine containing products in your pond. These chemicals can adversely affect the growth of your prized lily.
Regards,
Jeff Gray

Interestingly I put in a baby gate in the shape of a box (white), the thing is as clean as the day I put it in last fall. No algae whatsoever. Chara is here and there, and I planted a bunch of, um, the grass-like plants I collected up in the ADK. I think the CLPW is finding and capturing the free nutrients in the water before other plants can get to it. New pond, low nutrients.

Lsquid - I looked in earlier posts in this topic and could not see where you said how big your pond is containing YP,BC,WE. How big is your pond?

Its in my signature ;-), 0.6 acres, average 9' when at full pool, 13' max.

my pond is probably very similar to yours the water in mine is cryatal clear and i can easily go swimming and see every thing with goggles. i too had clpw in my pond and it is its highest in june and it slowly dies and is almost all gone by august but it always comes back every year at the same time and will die at the same time. it doesnt really move to areas that its not alreday there. it is really nothing to worry about plus it looks cool underwater and offers great cover for little fish if there are bass or crappie in your lake.

Another update,
It seems that where I have sediment wash-in, the CLPW had gone berserk. Other areas of the pond have very little of it. The area with the sediment grows at a rate of ~3 inches PER DAY in 50-60 degree water.

I am going to drop in some grass carp to keep the bushes trim, I would like to keep some plants, just not an incredibly thick mat of the stuff.

So it looks like CLPW likes rich sediments to grow in. Other parts of the pond are basic clay, it it doesn't seem to take hold there.

Soo... two years later and I have NOT treated the CLPW at all, and it is not a problem whatsoever any more. Sure it is here and there, but for the most part it is tame in my nutrient poor pond.
Far less coverage than I expected, way better than I dare hoped! If it were going to go nuts, it would have been this cool summer. The Koi may be denting it also.

Sometimes it is best just to relax and not rush into fixing a "problem" when it really isn't one. Turns out the stuff makes excellent cover for fish fry, clarifies the water well for swimming, and is somewhat aesthetically pleasing. Better than nothing but chara and FA. The ducks keep devouring my eel grass, so no hope there.

Many years later (Wow, time marches on!) I still have not treated CLPW. This may be the first year where the swimming area to where the float raft goes is getting choked off. I wanted to get some paper shell crayfish in hopes they can convert some plant matter into usable food for the BCP and the lone bass, but they are not available until June, which is a bit late for this year to get a leg up on the plants.

I may finally pull out the big guns and spot-treat areas we like to swim in and leave the other areas alone. I like the plant in there as without it I don't have a heck of a lot of cover otherwise. But in contrast to this, I have never had a bloom, and my recruitment is pathetic for lack of phytoplankton to support the newborns. I blame that on the nutrient sucking ability of the CLPW.

https://smithcreekfishfarm.com/products/aquathol-super-k

The CLPW certainly is responsible for water clarity being absurdly drinking water clear. Each spring around now (April/May) I can see smack to the 12ft+ bottom where there aren't weeds. The fish all chill under the dock as they are quite uncomfortable being exposed in the clear water.

My biggest problem? My inflatable boat popped. I want to get a small hard-bottomed rowboat for pond work, so getting out on the water is a bit of a problem.

I'm the former manufacturer of the Jenson Lake Mower, invented by Mr Ben Jenson of MN. (I retired and sold the business to Elastec, Inc. in 2020, so I am thankful it will hopefully survive me.)

Feedback from our customers was very positive for CLPW. They said they saw a significant reduction in regrowth when they cut before the seeds formed. We found that to be true for many aquatic plants.

But if the CLPW can grow from fragments, won't cutting it actually make it spread faster?

I don't think CLPW spreads from stems nor leaf fragments. CLPW is an annual plant. However CLPW does spread from its seeds in the seed head and the turions that develop in the axils of some of the leaves. The turions grow and develop as the plant matures. I think there is a point in time of growth or development where the turion becomes viable to produce a sprout of a new CLPW plant; similar to any plant that produces seeds. IMO not all newly developing seeds nor turions are active for new growth and it takes a stage of maturity for regrowth ability of a new plant. If the CLPW can be cut or removed before the turions are viable or mature or start to develop then non-turion parts of the plant will not re-sprout into a new plant. This assumes the seed head of the CLPW also has not fully developed.

A turion is a resistant plant bud that is found in certain aquatic plants, and can allow the plant to survive winter in the vegetative state (i.e., without setting seeds). The word “turio” is latin for a shoot or sprout (shoot in the sense of a plant stem and leaves), and is used in this case because a bud can develop into a shoot, as might happen with the turion in the late fall or spring after the ice has melted.

Bill, that's exactly what I thought too, but then I see a lot of references saying that it can spread by parts of the plant too, not just the turions or the rhizomes.

https://www.seagrant.wisc.edu/our-w...s-fact-sheets/plants/curlyleaf-pondweed/

esshup - That SeaGrant page does not even mention turions although it does show a turion. I think they consider the turion a plant fragment which technically it is a fragment of the plant. The wording on the page is general and it does not distinguish the growth activity or ability among stems, leaves, and turions. I defy anyone to show me how a leaf. stem or leaf & stem will sprout into a new plant for the specie CLPW. If we pin the author down to specific details I think they were referring to a turion as a plant fragment. I did not get an A+ in Aquatic Vascular Plants in grad school for being a dummy.

Lol on the last statement!

Having a heck of a time with the boat issue, then remembered I have a frikken fiberglass canoe unused hanging from the ceiling of my garage. May be a bit large for the purpose, but it will work. I am thinking I bonked my head on it one too many times, and that is why I forgot about it. I stopped using it as it was shedding fiberglass and my little guy has very sensitive skin. Went canoeing with him in that, and he became an itchy welt. It's been in the garage ever since.

Contacted a local pond service company, and it seems all they want to work on is wealthy people's ponds and water features. Outrageously expensive to treat paying someone else. Plus, they claimed you cannot get the herbicide in NY without a license while I was looking on a website for a pond supplier an hour drive from me with it for sale for NY residents. Trying to claim they were the only way to treat. Done with them.

If Bill Cody said it then I believe it!

Fingers crossed, but normally this time of year the CLPW is nearing the surface with cold and sunny days. I don’t see it yet at all. It was a very mild winter, so more sun than usual making it to the bottom. I would expect the CLPW to be going nuts… but it is not.
It is quite possible that the papershell crayfish are nipping the plants in the bud! Hopefully not too much as I would rather not have an algae bloom, but it sure is promising if they are turning plant into edible biomass and keeping the pond swimable.

What is your pond's water temperature? Keep watching for weed growth to show as the water gets above 55F. Then I think at least some stems with leaves will show up at they quickly 'reach' for the surface. I do hope your crayfish are reducing the growth of the CLPW however IMO crayfish are very vulnerable to predation on bottom areas to eat early growth of CLPW. I have seen with my Aqua-View CLPW 6"-12" tall on the bottom in mid winter under ice. Crayfish are still pretty dormant and not real active and do not eat very much when water temps are below 50F. Does the pond have bass 12"-16"? Then crays eating bottom weed growth away from dense structure are easy meals for hungry bass.

I currently have no bass, just the koi are the primary predators of the crayfish, then perhaps perch. Haven’t see a WE in a few years. I wanted to get the crayfish well established before LMB, but was waiting to see what happens with the CLPW.

It’s been a very screwy year. The water temps got up to about 50 at the surface in March before reality struck and it froze over two weeks later. It’s back to about 42 yesterday, but it was 78 today, so expecting temps to rise.

The water was clear enough to see the bottom before it rained a lot last week, and I could see a few CLPW plants coming up, but nowhere near the density the year prior.