Do Chickens Eat Duckweed? Yes, but Mind the Pond

Yes, chickens eat duckweed. In the one trial I found that gave chickens a choice of greens, duckweed came first. Researchers in Cambodia set chopped greens out in separate troughs for 40 young chickens and wrote down what happened. “Every feeding time, chickens ran to the trough with duckweed first”.

The old version of this page said the opposite, that chickens turn up their beaks at it. That’s gone. What’s left matters more for your flock. Duckweed is mostly water, it can’t stand in for a laying feed, and the pond you scoop it from matters more than the plant does.

I read 10 sources for this page, and you’ll find them all listed at the bottom. Three are feeding trials published in journals. One is Feedipedia, the animal feed database FAO runs with French research partners. Four come from university extension services, from Pennsylvania down to Alabama. The last two are Minnesota’s Department of Natural Resources and the Merck Veterinary Manual. Where they give a number, I give you the number and whose it is.

One note on the photos. The hens at the top are Saxon hens in a German backyard, a moment after their keeper threw some green garden clippings into the run. That’s not duckweed. I couldn’t find a free photo of chickens eating duckweed that I could check was real, so I’d rather tell you than pretend.

The short version.

• Chickens eat it. In a Cambodian trial they went for duckweed before water spinach or taro leaf.
• It’s 92 to 95 percent water, so a heaping scoop is mostly water.
• Its protein runs from 7 to 45 percent of the dry matter, depending on the water it grew in.
• The laying-hen trials fed dried duckweed meal mixed into the feed. Egg output held, and yolks got more color.
• In a Vietnamese trial, chickens on cut-back feed couldn’t eat enough fresh duckweed to make up the gap. Keep the feeder full.
• The pond is the big question. Sewage and farm runoff can end up in what you scoop, and so can weed killer or a toxic algae bloom.
• If wild ducks and geese use that pond, keep your flock away from it. That’s the bird flu advice.
• Give it as a treat, from water you know, rinsed, and no more than they’ll finish in 5 to 10 minutes.

Yes, and in One Trial They Ran to It First

The trial is by Kong Saroeun and three colleagues, published in 2010 in Livestock Research for Rural Development. They split 40 local chickens, 60 days old, into 4 pens of 10. For 4 weeks every pen had broken rice plus three chopped greens to pick from: duckweed, taro leaves and water spinach. Fresh greens went out 4 to 5 times a day.

Duckweed won, and not by a little. Counted as dry matter, the birds ate 3.9 grams of duckweed per head a day. Water spinach came to 2.0 grams. Taro leaf? Just 0.02 grams. The authors called duckweed “the most preferred”, and you’ve already read what they saw at feeding time. In fresh weight, they put duckweed intake at 61 to 116 grams a day.

One more result from that paper is worth knowing before you plan around it. In a second, shorter test, the chicks “did not gain weight on duckweed, except on the broken rice diets, and had normal growth on soybean meal”. So yes, they love it. Loving it doesn’t make it a feed, and the rest of this page is about why.

What Duckweed Is, and the Green Stuff That Isn’t

Duckweeds are tiny plants that float free on fresh water all over the world. Penn State Extension says that duckweed and its cousin watermeal “are the smallest flowering plants known”. A duckweed plant is 2 to 6 millimeters across, about the size of a pencil eraser, with a little root hanging under it. Watermeal has no roots at all and runs 0.2 to 1.5 millimeters, about a pinhead.

You may know it by another name. Minnesota’s Department of Natural Resources lists lesser duckweed, duck’s meat and water lentil. It also says that from a distance “duckweed is often mistaken for algae”. You can tell them apart up close. Duckweed isn’t interconnected the way stringy filamentous algae is, so a handful falls apart into separate little plants. Watermeal, the DNR says, “resembles green cornmeal floating in the water”.

That difference matters, because other things turn a pond green too. If what you lift out hangs together in strings, it’s algae, not duckweed. If the water itself looks like pea soup or spilled paint, the Merck Veterinary Manual says that’s one way a cyanobacteria bloom can look, and you’ll read below why you don’t want hens near one. The pond in the photo above is in a botanical garden in Bayreuth, Germany, and you can see it’s crowded with more than one kind of tiny floating plant.

Its Protein Depends on the Pond

The protein number is where duckweed gets oversold. Feedipedia puts its crude protein anywhere from 7 to 45 percent of the dry matter, “depending on nitrogen availability”. Duckweed from natural waters, ponds and ditches included, has been reported at 7 to 20 percent. Grown in water that’s been enriched on purpose, it can reach 30 to 40 percent.

The trial duckweed sat near the top of that range. The Cambodian plants (29.2 percent protein in the dry matter) grew in farm canals fertilized with effluent from pig manure. The Vietnamese trial collected its duckweed from natural ponds, and it still averaged 38 percent. Feedipedia’s own average across 15 analyses is 29.1 percent. So the range is wide, and you can’t see where your pond falls by looking at it. Feedipedia’s advice is to assess duckweed’s nutrient content before you feed it to livestock.

Still water like that Berlin forest ditch is where these plants do well. Penn State says they’re usually found in “nutrient-rich ponds with stagnant or little flow”. Hold on to that word, nutrient-rich, because it comes back further down.

What the Laying-Hen Trials Measured

If you keep hens for eggs, these are the studies you’d want, and there aren’t many. Feedipedia says work with laying hens “has been more limited than in broilers but has been encouraging”.

The newest one I read came out in 2023 in Animal Science Journal. Baghban-Kanani and Oteri, with their colleagues, fed 432 Hy-Line W-36 hens, 60 weeks old, for 10 weeks, with duckweed at 0, 7.5 or 15 percent of the diet. They summed up the result in one line. “Duckweed did not affect egg output or weight, but it improved yolk color”.

Two older trials point the same way. In a Peruvian study by Haustein and colleagues, published in Poultry Science, egg production and egg weight held with dried duckweed at up to 40 percent of the diet. The best level was 15 percent, and that diet gave more egg pigmentation than the control. A 2011 US study by Anderson and colleagues found that dried duckweed at 12.6 percent “did not impair the performance of laying hens”, and Feedipedia adds it “could also be a means of enhancing Omega 3 levels in eggs”. I read those two through Feedipedia’s summaries, not the papers themselves.

The yolk color makes sense. Feedipedia lists duckweed’s carotene at 600 to 1,000 mg per kg and says its pigments “can contribute to skin and yolk colour”. The eggs in the photo are just eggs, by the way. Nobody says what those hens ate.

Now the part all three trials share. Every one used dried duckweed mixed into the hens’ feed. The 2023 duckweed spent 48 hours drying in the sun, then 24 hours in an oven. Du Thanh Hang, writing about the Peruvian work, pointed out that “the duckweed was dehydrated to a dry meal”, and that drying it “is rarely feasible at the level of small scale farmers” because it’s about 95 percent water. A Dutch trial Feedipedia cites needed 30 hours at 40°C to get it from 95 down to 10 percent moisture.

So a 15 percent figure from these papers isn’t a scoop of pond weed. It’s dried meal, weighed into the ration. Nobody in these trials tossed wet duckweed into a run, so they can’t tell you what that does to your egg count.

Fresh Duckweed Can’t Stand In for Feed

For fresh duckweed, the trial to read is Du Thanh Hang’s, from Vietnam, published in 2013. Forty-five Luong Phuong chickens, 30 days old, got a maize and protein mix either as much as they wanted or cut back to 60, 70, 80 or 90 percent of that. Every bird also had fresh duckweed whenever it wanted it, washed in clean water first.

The less feed they got, the more duckweed they ate. On full feed it was 115 grams a day, and on 60 percent it was 172 grams. It wasn’t enough. The chickens “were unable to eat enough fresh duckweed to compensate for the restriction in the concentrate allowance”, the paper says. Growth and feed conversion got worse as duckweed’s share of the diet went up, and “there was no saving in concentrate usage per unit live weight gain”.

Even with full feed in front of them, duckweed made up 7 percent of what those birds ate, counted as dry matter, and 15 percent of their protein. By my arithmetic, 115 grams is about 4 ounces of fresh plant. That sounds like plenty until you remember it’s 92 to 95 percent water.

Feedipedia’s poultry notes say the same in other words. Duckweed’s energy value for poultry “was reported to be relatively poor”, and young chicks “cannot consume enough duckweed due to the bulkiness of the material”. Some duckweeds also carry oxalic acid, which Feedipedia says “limits intake in livestock”. In small village flocks, results were “variable”.

So keep your laying feed in the feeder all day, and let duckweed be the extra. An Alabama Extension sheet puts a laying hen at 100 to 150 grams of feed a day, roughly a quarter pound. Our chicken feed calculator runs those sums for your own flock, and the Rhode Island Red feeding guide walks through layer feed and oyster shell.

Which Pond It Comes From Matters Most

This is the part I’d think about before anything else. Duckweed takes up what’s in its water. That’s why it’s used, Feedipedia says, “to reduce the chemical load of sewage ponds”. It’s also why Feedipedia strongly advises against feeding duckweed grown on industrial wastewater with heavy metals and organic toxins, and lists pathogens, heavy metals and organic toxins as the main public health concerns of duckweed farming.

Then there’s the reason a pond fills up with duckweed in the first place. Penn State calls any overgrowth “a symptom of excessive nutrients”, and says those nutrients may come from runoff from barnyards and crop fields, septic systems, lawns, even golf courses. A thick green mat tells you something about what drains into that pond.

That same rich water feeds algae blooms. The Merck Veterinary Manual says cyanobacteria, the blue-green algae, “can appear as blue-green, green, brown, red, or white scum on the water surface”. A bloom “may appear like pea soup, spilled paint, or striations in the water, or they may be invisible”. Not every one is toxic, Merck notes. But its list of reported deaths from one of their toxins, anatoxin-a, includes waterfowl, and it reports poisonings in birds from another. A pond with a scum on it is one I’d skip, and the scum in the photo above is the kind I mean.

Then weed killers. Penn State lists herbicides labeled for duckweed and says chemical control is often needed every year, sometimes more than once. If anyone treats that pond, read the product’s label before anything from it goes near your hens. Penn State’s own line is “Follow the herbicide label carefully”.

My rule from all this is mine, not a source’s. Only feed duckweed from water you know. Skip road ditches and runoff ponds, anything downhill of a septic field, and anything with a scum or a weed killer history. For a quick second opinion on other treats, our can chickens eat it checker covers the usual ones, and so does our list of what not to feed chickens.

Wild Ducks on That Pond Bring a Bird Flu Problem

Penn State says duckweed and watermeal are “especially important as a food source for waterfowl”, and that ducks and geese move them from pond to pond, lodged between their feathers. So the pond with the best duckweed may well be one wild ducks use.

That’s the problem. In its January 2022 bird flu update, Ohio State University Extension passed on USDA’s warning that “wild birds can be infected with HPAI and show no signs of illness”. HPAI is highly pathogenic avian influenza. Ohio State’s biosecurity advice for backyard poultry includes making sure “your domestic birds cannot access areas migrating birds may visit, such as ponds, puddles, other open water sources”.

I didn’t find a study on bird flu carried on duckweed itself, so I won’t claim one. But if you scoop it from a pond where wild ducks feed, you’re carrying that pond’s water and whatever’s on the plants straight into your run. If you ever see sick birds or unusual deaths, that same update asks you to report them through your state veterinarian or USDA’s toll-free number, 1-866-536-7593.

How to Offer Duckweed, If You Do

If you’ve got a clean source, here’s how I’d hand it out, going by the sources above.

• Pick water you know. No runoff, no sewage, no scum, no weed killer, and no wild ducks.
• Rinse it. The Vietnamese trial washed its duckweed in clean water before the birds got it.
• Put it out beside the feeder, never instead of it. Fresh duckweed couldn’t make up for cut feed in that trial.
• Keep it small. Colorado State Extension’s rule is that treats make up no more than 10 percent of the daily diet. Don’t put out more than the flock can eat in 5 to 10 minutes, so leftovers don’t draw nuisance animals.
• Throw out what they leave. Fresh duckweed is “extremely bulky and perishable when harvested”, Feedipedia says, so a wet pile won’t keep till tomorrow.

It’s a warm-weather extra. Feedipedia says duckweed can double its mass in 16 hours to 2 days when conditions are right. It grows best between 17.5 and 30°C and tends to die once the water passes 35°C. In cold weather a starchy frond called a turion sinks to the bottom of the pond, so don’t count on a winter supply.

And if a hen seems off after eating anything that came out of a pond, call a vet who sees poultry, and tell them where the water came from.

Updated October 2026: rewritten from the sources below and checked line by line. This page’s old version opened with a first-hand story about a backyard pond and a flock that ignored a pile of duckweed. This byline can’t stand behind it, and the Cambodian trial found the opposite, so it’s gone. It said duckweed has more protein than soybeans, and the sources give a range of 7 to 45 percent of the dry matter that depends on the water. Its blanching and baking steps, its storage advice and its mixing ratios came from no source, so they’re cut. So are its claims that dried duckweed in nest bedding repels mites, that chickens self-regulate what they eat, and that some hens are allergic to duckweed. Its compost tea dosing, its section on selling duckweed to farms and its parasite advice for ducks are cut for the same reason. Its old pictures are gone too.

Sources

• Feedipedia: Duckweed (Heuzé V. and Tran G., 2015; a programme of INRAE and CIRAD with AFZ and FAO).
• Feed selection and growth performance of local chickens offered different carbohydrate sources in fresh and dried form supplemented with protein-rich forages (Kong Saroeun, Brian Ogle, T R Preston and Khieu Borin; Livestock Research for Rural Development 22 (12), 2010).
• Effect of offering fresh duckweed (Lemna minor) to chickens fed restricted levels of maize meal and protein concentrate in confinement (Du Thanh Hang; Livestock Research for Rural Development 25 (6), 2013).
• The effects of replacing wheat and soyabean meal with duckweed (Lemna minor) and including enzymes in the diet of laying hens (Baghban-Kanani P., Oteri M. and colleagues; Animal Science Journal 94: e13888, 2023).
• Penn State Extension: Duckweed and Watermeal (Bryan R. Swistock with Mark Hartle and Andrew Curtis, updated May 19, 2025).
• Minnesota Department of Natural Resources: Duckweeds and Watermeal.
• Merck Veterinary Manual: Algal Poisoning of Animals (Karyn Bischoff, last updated September 2024).
• Ohio State University Extension: Update on Highly Pathogenic Avian Influenza (January 2022, quoting USDA APHIS).
• Colorado State University Extension: Raising Poultry the Organic Way: Disease Control and Feeding (Howard Enos).
• Alabama Cooperative Extension System: Feeding the Laying Hen (ANR-2913).

Sources checked October 26, 2026. My arithmetic from these sources: the 4 ounces. We aren’t vets. If a bird looks sick, call a vet who sees poultry.

Related read: How to Raise Chickens for Eggs — Instant PDF download. Secure checkout by Stripe