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Duckweed Hunting in a Car

March 8, 2016

wild harvetsing duckweed in Uganda

I just spent the past week and a half traveling in Uganda and Kenya on business. While enjoying a nose-to-the glass focus on all the new sights,  the back of my brain was ever on alert for duckweed.

Finally I spotted some in a ditch and shouted, “Duckweed!” Everyone in the car cracked up because they knew me too well. Our driver promptly pulled over and we all made a mad rush to dig up empty water bottles and plastic bags.

While the water looked clear enough to see what might be lurking, we hailed a young man who was more than happy to wade out to collect water samples and as much duckweed as possible. Yeay! A new Lemna strain that I’ve not seen before. We got it home and safely transplanted. Am tickled because it looks super healthy and not going into shock from its ordeal.

A few tips for YOU when you have neural wiring fine-tuned to spot duckweed from the AC comfort of your own vehicle. (trust me, I have done this for over 120,000 miles)

  1. If you are driving, drive and “Don’t do like I do” and duckweed hunt at the same time. Promise me…
  2. Ditches near fertilized lawns or golf courses are prime game. So are rice paddies, marshlands, drainage ponds from plant nurseries, wastewater lagoons, etc…
  3. Plastic water bottles are terrific for water samples. Any old plastic bag that’ll hold moisture is good for actual duckweed for up to 24 hours and NOT left in a hot vehicle to cook to death.
  4. If you are the water chemist type and can do simple water quality analysis of your water samples, try to at least get the pH, ammonia, phosphate, and total dissolved solids of your samples. This’ll help you know how to tweak your water when you get home and give your duckweed samples something similar to what they were used to in the wild. or…
  5. Replant in YOUR water system and hope for the best.
  6. Back to harvesting, a net and pole in the trunk of your car will make harvesting a whole lot easier and safer than this young man who was vigilant for crocs while he harvested this duckweed. (I wouldn’t have been able to forgive myself had he gotten attacked but he was so willing to do it for a dollar… $2 a day wages in this region.)
  7. If you feel you MUST harvest from a wastewater lagoon, don’t do it unless you have protective gear on and soak everything down with bleach afterwards. Then you have to  treat the duckweed like a red-headed stepchild for a long time in terms of potential germs. Not worth it. Let the pros handle it.
  8. Now that I’ve absolved myself from any potential lawsuits, do go out and enjoy hunting for duckweed from a vehicle. It’s a fun little treasure hunt. Enjoy!


The Nitty-gritty on Duckweed

February 28, 2016

Yes, yes, I know… Over the past three years, my blog about duckweed has drifted to everything from duckweed to decks to wood-fired ovens to skinny-dipping in hot tubs. As there are now nearly 200 posts, it is getting hard for folks to find duckweed info they need. .Am going to fix that here shortly with a new page on the site. Just give me a couple weeks..

I am  traveling abroad quite a bit these days, currently starting duckweed pilot projects  in four new countries. . I’d always dreamed of doing this sort of thing and what do you know- wishes do come true.

Playing catch up with you all on the nitty-gritty of duckweed production and applications:

  1. Duckweed has value as an animal feed for just about any animal you can think of.  Peacocks like it. So do rabbits. Haven’t tried it on monkeys yet though.
  2. If you come to me with a bioenergy project with duckweed, I will run, screaming in the other direction. Only exception is waste water to duckweed and then it had better be in country where energy prices are through the roof. Do I sound a bit frustrated here?
  3. Expect to be disappointed if you try to use off-the-shelf fertilizer on duckweed. It will not work unless you tweak the heck out of it.. Start with mimicking duckweed’s former natural habitat- water, mud, a dilute waste nutrient contribution (a bit of manure, etc…) a bit of shade,  wind protection, etc…Which leads me to #4
  4. Consider that you are culturing an eco-system, not a mono crop. It’ll make your life easier.Even duckweed needs beneficial relationships with bacteria, etc…
  5. Duckweed’s primary limiting factor is nitrogen. Shoot for 20ppm ammonium if you have a tester. Build up duckweed’s tolerances and if all other nutrients are there and your pH is around 7 or lower,  you can ramp up to 60ppm. ammonia/ammonium. Just watch out though. You’ll have more duckweed than you know what to do with. What can get you there? Manure from cows, hogs, goats, or sheep will do it but don’t overdo it. Biomethane effluent works well but with ALL forms of fertilizer- test the heck out of it first in graduated amounts and see what works best.


Duckweed for Ducks

February 9, 2016

Am in Indonesia this month, working on a duckweed-related venture. Part of what I love about my job is getting to explore the unexpected in search of duckweed strains. Last weekend, a duckweed hunt took me to the communities around the international airport of Jakarta

. My colleague and I used Google maps of the area, then narrowed down to a few sites that looked promising for duckweed. We rented a taxi for a few hours ($10 for three hours!). We through heavy traffic and narrow alleyways in search of the elusive duckweed ponds that looked easy to access from a Google map but were another story to find with the tiny unnamed streets we encountered. We got out several times to walk a few more blocks to where the concrete or tin homes lined fish ponds and rice paddies.

We were happy to at last find healthy duckweed thriving in water that smelled like a sewer and laden with bobbing bottles and trash of all sorts. Nearby, the rolling, acrid smoke of a burning trash dump made our eyes water. We spoke with a local carp grower who was busy harvesting duckweed with a small net and bucket. He said that the duckweed made his fish taste better.

Later, we ran across another farmer harvesting duckweed for his ducks. He said they had better weight gain and eggs and meat tasted better as well. He invited us back to his home and watch his ducks get fed their evening ration of duckweed. We got to see his backyard where he raises ducks, fish, and some food crops. We got to meet his family, and had lots of photo ops with the neighbors. As we returned to the waiting taxi laden with duckweed samples, a young girl put her arm in mine and called to her friends to come see her visitor as we walked along. Many people came out of their homes and I greeted as many as I could. Fun times.


Ducks eagerly gobbling duckweed.


Mr. Mang harvests wild duckweed every evening to feed his ducks.


The Mangs and a couple of cute neighbor kids.

Sorry, no Duckweed Right Now

December 10, 2015

For some reason, am suddenly getting many requests for fresh duckweed samples here in the early part of winter. Even though I made that offer two years ago and even  personally paid postage on envelope-sized amounts, am still willing to fulfil requests BUT with the following caveats:

  1. Wait until late spring (May) when my ponds are actively growing again.
  2. Send me your address in April or May along with….a. $2.00 for a tbsp of fresh duckweed in a zip lock bag in a regular envelope or b. $8.00 for as much as I can pack into a USPS small Priority box. (roughly 2 cups)   or  c. $90 for a five gallon bucket size (or shipping and container plus $30- whichever is cheaper)  This is a mixed species: Lemna turionifera and Wolffia minutia.
  3. For summer orders of solar-dried duckweed in lots of 1  kg to 1 metric ton, please email me at

On a perso1209150746.jpgnal note, am restoring my grandfather’s 80 year old rocking chair. Don’t have a bandsaw or I’d make replacements for the broken wood pieces. My grandfather  spent most of his senior waking and napping hours in this rocker. Fond memories.



Oh yes, and a VERY fun project- am brewing my first-ever batch of Christmas cheer- a Pilsner in a five gallon bucket.




BSF and Duckweed

November 19, 2015

Here is a terrific link to details on how to rear black soldier flies. Mention was made about feeding fresh duckweed to BSF larvae. A little tip- don’t try to ONLY fresh duckweed.  Integrate with other vegetation and watch the moisture content. (around 60- 70%)

The first time I ever raised BSF was by accident. I found them in my kitchen scrap barrel. When the population ramped up, I watched them devour 6 inches deep of food scraps a day. Watching that seething mass of wriggling larvae was fascinating. I called my kids out to see what was going on. They took one look, started shrieking and ran for the house.

I guess I should have warned them.

Video courtesy Living Web Farms


Duckweed: Stress or Passion?

November 1, 2015

Sugar Cane in Kentucky

October 24, 2015

 Brought a couple of these 6 foot tall babies back from my biz trip to Florida last week. Bought them at a farmer’s market in Homestead. I had driven through at least one hundred miles of sugar cane fields, watching the trailers hauling chopped sugar cane to the processing plant in Belle Glade, FL and was totally mesmerized by the whole process. This is a half a billion dollar a year industry. Man, we go through a LOT of sugar!

On the way home,  I pulled into a Taco Bell drive thru and a nice young teen asked excitedly, “Is that sugar cane?” (Due to their length, I had to cram the cane in on top of luggage sideways, smashed up against the windows.) When I said yes, his eyes sparkled and then teared up. He said that as a child, he used to chew/eat/suck on it on his grandfather’s farm but hadn’t seen sugar cane since. I offered to cut him off a chunk if he had a sharp knive. Alas, Taco Bell did not keep any sharp knives laying around, so I had to drive off, feeling his wash of memories as though they were my own

.I decided to create sugar cane memories for MY kids so I threw a pizza party- first firing of my WFO this year and introduced sugar cane to my gang. I think I was more excited about it than they, but they did demolish every bit I had prepped. asked a lot of questions, and we went another two rounds. The flavor is a light, crystal sweet and very refreshing.Since I did not have a sugar cane juicer handy, we had to chew or suck on the cane to break the cell walls to release the juice. Fun but I found myself mentally rummaging through my basement storage of old juicers, grinders, etc… to do the job more efficiently. Not worth it for this small amount which led me to my next challenge- raising sugar cane in Kentucky!

I cut 6″ chunks of cane and planted them horizontally in several pots with a mix of dirt and sand and have all in my unheated sun room.  According to the Internet, these will sprout in the spring. I also placed a piece in a vase of water where I am rooting a vine cutting. In less than a week, the darned thing is already rooting and a bud swelling up. I have no illusions about farming a tropical plant in a temperate zone- these will all be potted plants on my deck or in my home and with luck, will shoot upwards of 8-12 ft in the summer. I can cut them down in the fall, bring the pots into my sun room to overwinter and have sugar cane to juice and experiment with.

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