Japanese Knotweed: Dreadable Edible

by Green Deane

in Edible Raw,Greens/Pot Herb,Plants,Recipes,Roots/Tubers/Corms,Vegetable

 

Japanese Knotweed in Fall Flower

Japanese Knotweed gets no respect. Nearly everywhere it grows it’s listed as a prolific, noxious, invasive, dangerous bad-for-the-world, the-sky-is-falling weed. Oh by the way, it’s edible. Might be even really healthy for you…. pesky weeds have that habit.

Young Shoots in Spring

Japanese Knotweed is listed by the World Conservation Union as one of the world’s worst invasive species. Perhaps it should be planted in countries where starvation is annual. Introduced into Great Britain by 1825 Japanese Knotweed has been on the decimation list for more than 30 years and has to be disposed at landfills licensed to handle the dreaded edible. In fact they spend some two billion pounds to combat it annually, which as of this writing is about three billion dollars a year. It increased the construction cost of the 2012 Olympic stadium by some 70 million pounds. Japanese Knotweed is also “invading” New Zealand, Australia, and Tasmania. It arrived in North America in the late 180os and is officially found in 39 of the 50 United States, probably more, and six Providences of Canada. It’s an invasive weed in Ohio, Vermont, West Virginia, New York, Alaska, Pennsylvania, Oregon and Washington. About the only place where they are not upset with the plant is where it’s native, southeast Asia. What do they know the rest of the world doesn’t? It is said that Japanese Knotweed out lives the gardener and the garden.

Knotweed Creats a Knot

Knotweed, in the Buckwheat family, is not liked in western nations because it grows around three feet a month, sends roots down some 10 feet, grows through concrete, damaging roads, dams, buildings and just about anything made by man. It’s a pain in the asphalt. Forages take advantage of it eating — raw or cooked — young shoots, growing tips of larger plants and unfurled leaves on the stalk and branches. Many folks say it tastes like rhubarb but I think a lemony green is more accurate, crunchy and tender. For the health conscious it is a major source of resveratrol and Vitamin C … a noxious weed AND very healthy. Tsk…Tsk… The California Department of Food and Agriculture and the book Cornucopia II both say the rhizomes are edible. No references are given as to how to cook them nor have I tried. Usually the roots are used medicinally. Giant Knotweed, Polygonum sachalinense (Fallopia sachalinensis) is similarly consume except its fruit is eaten as well, or stored in oil. Incidentally, the Giant Knotweed was “discovered” on Sakhalin Island, north of Japan, by Dr. H Weyrich, surgeon on the Russian expedition ship Vostok commanded by Captain Lieutenant Rimsky-Korsakov, older brother of the composer N.A. Rimsky-Korsakov… it’s a small world afterall…

Note branch bends at nodes like an Eastern Redbud

Botanically take your pick: Japanese Knotweed is known as Fallopia japonica, Polygonum cuspidatum, and Reynoutria japonica. In Europe they prefer Fallopia japonica (named for Gabriello Fallopia, 16th century Italian anatomist who “discovered” fallopian tubes. Japonica means Japan.  In North America it is known as Polygonum cuspidatum, which makes a lot more sense to me. I see nothing fallopian tubish about the plant whereas Polygonum (pol-LIG-on-um) means many joints and the plant does have that. Cuspidatum (kuss-pid-DAY-tum) means sharply or stiffly pointed, and that it is.

Other names names include fleeceflower, Himalayan fleece vine, monkeyweed, Huzhang, Tiger Stick, Hancock’s curse, elephant ears, pea shooters, donkey rhubarb, sally rhubarb, Japanese bamboo, American bamboo, and Mexican bamboo. The Japanese call it itadori (イタドリ) which is from Chinese and mean “tiger walking stick” or “tiger stick.” Best guess, and my thanks to Ala Bobb for the insight, is that the stick has stripes like a tiger. Sometimes it is called itodori which means “thread stick” a reference to the the thready flower. Two other names, in Chinese, are, 痛取 “pain take” and 板取 “board take”  In Engish we would reverse them, “take pain” and “take board.”

Lastly there is an ethnobotanical lesson in Japanese Knotweed: The Cherokee ate the cooked leaves. Shall we thus call it a Native American food? There are several examples of imported plants being adapted by the native population, no fools they. Those get reported as Native American food without the “when” being reported. Folks just assume they were eating or using said before the Europeans arrived.  Black Medic is another example. If I remember correctly it first came to North America around 1912, just a century ago. But it is listed as a Native American food because some western tribes did eat it once they knew what it was. It’s the same with a ground cover imported in the 1930s. The lesson is just because the natives ate a particular food it does not mean it was around before outsiders arrived. It’s kind of like saying chocolate pudding was an Aborigines’ food.

Green Deane’s “Itemized” Plant Profile: Japanese Knotweed

Rhizome runners can extend 60 feet

IDENTIFICATION: Polygonum cuspidatum: A semi-woody perennial, fast growing, hollow, bamboo-like stems forming dense, leafy thickets, woody with age. Young shoots are red. Leaves simple, toothless, hairless, alternating, broadly ovate with a pointed tip, 3 to 6 inches long, 2 to 4½ inches wide, on a long leaf stem. Flowers branching in spike-like clusters, individual flowers are 1/8 inch across, white to greenish or pinkish, with 5 petals, 8 stamens. Male and female flowers separate (dioecious.) Female flowers can produce small 3-angled black-brown fruit. Seed production is uncommon.

TIME OF YEAR: Purple shoots appear in spring, flowers late summer, early autumn.

ENVIRONMENT: Riverbanks, roadsides, moist, disturbed areas.

METHOD OF PREPARATION: Young shoots, growing tips, young leaves boiled or steamed and eaten like asparagus, or chilled and served with a dressing. Can be used in pies. soups, aspics, sauces, jams, chutneys even wines. The roots, actually rhizomes, are sometimes eaten. It is good fodder for grazing animals, including cattle, sheep, goats, horses and donkeys. Old stems have been used to make matches. It is high in oxalic acid so if you avoid spinach or rhubarb you should avoid knotweed.

Recipes from Herbalpedia

Japanese Knotweed Purée
Gather stalks, choosing those with thick stems. Wash well and remove all leaves and tips. Slice stems into 1-inch pieces, put into a pot and add ¾ cup sugar for every 5 cups of stems. Let stand 20 minutes to extract juices. Add only enough water to keep from scorching, about half a cup. Cook until pieces are soft, adding more water if necessary. They will cook quickly. When done, the Japanese Knotweed needs only to be mixed with a spoon. Add lemon juice to taste and more sugar if desired. Serve chilled for dessert just as it is, or pass a bowl of whipped cream. This purée is excellent spooned over vanilla ice cream or baked in a pie shell. Keeps well in the refrigerator and may be frozen for later use. (City Herbal)

Japanese Knotweed Bread
2 cups unbleached flour
½ cup sugar
1 ½ tsp baking powder
1 tsp salt
1 egg
2 Tbsp salad oil
¾ cup orange juice
¾ cup chopped hazelnuts
1 cup sweetened Japanese Knotweed Purée
Preheat oven to 350F. Sift dry ingredients together into a large bowl. Beat the egg white with the oil and orange juice. Add along with hazelnuts and purée to dry ingredients. Do not mix until all ingredients are added, and blend only enough to moisten. Do not over mix. Spoon gently into buttered 91/2-by-5-by-3-inch loaf pan. Bake about 1 hour or until a straw or cake tester inserted in the center comes out dry. Cool by removing from pan and placing it on a rack. For muffins, spoon into buttered muffin tins and bake about 25 minutes. (A City Herbal)

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{ 53 comments… read them below or add one }

1 Karen November 11, 2011 at 09:41

Hi Deane. We love/hate knotweed too. We have manged to cook up at least 5 recipes for this plant on our blog
http://the3foragers.blogspot.com/2011/05/japanese-knotweed-recipe-knotweed-jelly.html

As a kid, we used to whack each other with the dried stalks. In Florida, does the growth die back seasonally like it does here in Connecticut? Karen

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2 Green Deane November 11, 2011 at 10:11

Thanks… do I have you listed on my “resources” page?

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3 Lrong November 12, 2011 at 06:18

Greetings from Japan… found your blog while searching for Hyacinth beans… very informative blog…

Am happy to learn the name of this plant… we actually enjoy picking it from the hills and cooking it in the spring…

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4 Mary March 26, 2012 at 20:32

Does anyone know anything about the edibility of Silver Lace Vine (polygonum aubertii) ?

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5 Green Deane March 27, 2012 at 16:27

It is not listed as an edible in any of my references.

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6 Nicky Verity April 17, 2012 at 00:46

I’ve been stomping/pulling/cutting this stuff all Spring and wondering what it was. Nice to know I can eat it instead of just pulverizing it! The only other good thing about Japanese Knotweed is that it seems to combat erosion somewhat. Thanks for the info.

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7 Vern Rutter May 20, 2012 at 13:32

Here in WA state, USA, Knotweed is a major erosion problem. It displaces native riparian plants which hold the soil, then dies back in the winter when the rains come and fills Salmon redds with silt.

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8 Joseph July 7, 2013 at 13:36

I don’t understand how they can be a cause of erosion. The plant is decidious/herbacious, but it’s roots are what hold the soil together. They’re there year round.

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9 Marti September 7, 2013 at 17:58

The cause erosion because they will shade or choke out all other plants and then in the winter without the leaves the dirt below is bare of even grasses and so will erode under or around the knotweed.

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10 Keith December 10, 2013 at 20:07

well maybe they shouldn’t remove the leaf litter then. i’d need to see some real proof of this, it seems highly doubtable. If the winters are mild enough to fully decay the plants that dieback than the soil should be covered by winter annuals since the soil is bare. I don’t intend to sound rude, but it seems like a reasoning for government contracts to hand out tax payer money for genocide of the ‘invasive exotic’.

11 Roger March 25, 2014 at 12:22

I wouldnt blame knotweed, more blame on that has to be put on washigton states over cutting of the old growth forest which has caused most if not all the problems of silt and runoff into the redds and also all the logging roads built to close to our watersheds thus causing degradation of the salmon runs. Funny how the state gov agencies seems to put all the highly beneficial plants/ weeds everthing that has benefit to the health of our eco-system on the noxious weed list and wants to erradicate it with highly toxic chemicals that are destroying all the beneficial pollinators , bees, butterflies, flies birds etc. Just read the effects that neonictinoids and the effects of the new 2-4-d pesticides are doing to our bees and pollinators..purposefully by the EPA in the nsme of big money for the GMO seed giants. I hope people begin to wake up soon to whats really happening and begin to be more pro- active its our childrens futures that are going to have to grow up eating their poison. I challenge people to really look into this. A good advocate pesticide action network or oregon sustainable beekeeping.

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12 Gunnar Wordon April 18, 2012 at 17:34

Can I eat the leaves too?

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13 Green Deane April 18, 2012 at 21:40

As the article says, young leaves cooked are edible.

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14 Charles Clements September 6, 2012 at 02:14

I read some time ago in some book in the library that there were three hundred thousand plants classified and of them three thousand were editable. You are on one hundred and what? I hope you live long enough to tell us about all of them.

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15 Keith December 10, 2013 at 20:09

Haha I second that! You are by far my favorite internet source on plants. I wish they would put you on discovery channel or something.

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16 Greg September 25, 2012 at 19:39

Deane, what is the “ground cover imported in the 1930s” that native americans ate?

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17 Green Deane September 25, 2012 at 21:53

It’s a Dichondra.

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18 cris September 26, 2012 at 22:07

I wonder if the seeds are edible as well?
I have read on another site that they were, but it was the only place I have seen that information. I have a plant here that has a TON of seeds all over it…

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19 Green Deane September 27, 2012 at 05:18

The internet is a sewer of misinformation. It is the least credible source of information we have. I have no reference to the edibility of the seeds of the Japanese Knoweed. However, the seeds of some of the plants in the same genus, Polygonum, have been parched and eaten among them P. douglasii and P. convolvulus. Either that one website is making an assumption or knowns something not reported elsewhere on the internet or in publications. I do not use the internet for research. I use the univeristy library as well as my own private collection. I have no reference regarding seeds. I note Steve Brill, a forager who writes a lot about Japanese Knotweed does not mention seeds.

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20 Michael J. Trout October 8, 2012 at 12:32

I really enjoyed your article… there seems to be a lot of images Japanese Knotweed and all to me look different. I am launching a number of bee sanctuaries sin Japan… do you know if the bees like the flower? I am definely gonna try some of your recipes once I can figure out which of the many weeds growing is Japanese Knotweed… I have a better idea now at least what I am looking for.

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21 Laurie February 23, 2013 at 14:07

Saying bees like knotweed would be a vast understatement. When my knotweed blooms in late summer, it literally hums with bees, and if you stand underneath it, it’s like there’s snow falling as they work over the tiny blossoms. By the way, I’m so happy to learn that this so called ‘noxious weed’ is not only edible but healthy & medicinally useful!

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22 Amie May 9, 2013 at 20:49

The beekeeper my parents used to go to years ago carried Japanese Knotweed honey. He claimed it was one of the most nutritious honeys out there, if not the most.

He’s no longer around and my father is currently trying to locate another beekeeper who has even heard of Japanese Knotweed honey.

Good luck with your bees!

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23 Eric December 21, 2012 at 09:50

I thought the knotweed contained a fair amount of oxalic acid? About the same a ruhbarb? Thus be careful if you have issues with kidney stones etc.

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24 Marsha January 11, 2013 at 11:23

I’ve just recently found your site and have found it very informative. My question is this: is Japanese knot wood the same vine that in the south we call cud zoo vine? It’s everywhere covering trees and whole acres sometimes. If its an edible plant like ” Polk salad” I’m never going to starve.

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25 Green Deane January 13, 2013 at 17:32

No, Japanese Knotweed and Pokeweed are two very different species. Poke weed is edible boiled twice. Read my articles about it. Don’t get confused with the term Poke “salad.” It is really poke “salet” pronounced the same as salad. But it means ca ooked green. NEVER eat poke leaves raw.They can kill you.

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26 SqqqsMe February 7, 2013 at 09:57

Marsha,

Although they are not related, as the Kudzu is of the Pea family, Kudzu is highly edible. Enjoy! See source:
http://www.azcentral.com/style/hfe/food/articles/2007/03/20/20070320cookingkudzu0320.html

BTW, I grew up eating Poke Salet. Properly prepared as noted by Deane, it is an excellent cooked green.

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27 Greenspider January 23, 2013 at 10:33

In my yard the Japanese knotweed draws a TON of flies, a lot of different types too.
I put it away from the door hoping to draw flies from around the house.
Not too sure if it changed how many flies got into the house but I’ll keep it there anyway since it is a good source of edible plantlife.

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28 Steve April 22, 2013 at 23:53

Mr. Green Deane, so this is most definitely out of the intended scope of this post, however, this is the most in depth user online source for knotweed so I figured I’d try here….In a sustainable effort I am very interested in integrating knotweed into the fencing for my garden but I am worried about the initial threat of regeneration as well as the long term structural stability. I currently use sumac (which as a tree grows like a weed) and have no problems with regeneration as long as I let the cut stalks dry out a bit but I was curious about the resilience of the knotweed (I’d hate to accidentally transplant). Also, I recall building play forts as a child at my grandmothers house, cutting the stalks, staking them, tying them, but I can’t seem to recall how they stood a few days, weeks, months down the line. Do you have any insight as to the structural tendency of this weed. Does it harden like bamboo.

Thanks and great posting, this was a very enjoyable read.

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29 Green Deane April 26, 2013 at 15:44

It’s not a strong material

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30 Tom May 3, 2013 at 16:03

And to think I’ve been trying to kill these plants off. I simply pulled up young stalks in spring and harvested the growing tips and small tender leaves. They are not only edible but really very tasty, a mix of rhubarb, tender collard green, and a hint of artichoke. I simply cooked ‘em in salted water for two minutes, drained, and gave them a squeeze of lemon. Next time, I think I will add the larger leaves to the water first and give them about two minutes before adding the tenderest parts for the last two. Thanks as always.

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31 Scott May 7, 2013 at 15:10

I have these growing on a slope in my back yard. I ate them for the first time yesterday. I wrapped them up in aluminum foil, drizzled with olive oil and a little salt. It had a taste that i don’t think everyone would enjoy, but i loved it! Not as much as I love Purslane. Its a much better feeling when you can enjoy eating the weeds that used to frustrate you with the endless task of pulling them.

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32 Mary Berg May 10, 2013 at 15:43

There was a song about another type of “weed” and one of the lines went something like, “they cut and they burned and they burned and they cut. ” This reminds me of the way I have been trying to get rid of this knotweed for the past 10 years. Until recently, I had no idea what it was and could find no one else that knew. I finally had a professor at the university tell me what it was. I still figured I would have to get “radical” with getting rid of it until I did some research and found that it is managable and that it is also nutritious and has medicinal properties. I can’t wait to try some of the recipes. Now I am sitting here on this sack of rhyzomes and just smiling

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33 Florida Salon May 11, 2013 at 00:54

If anyone knows of any in Florida…PLEASE email me. I want it for Lyme treatment. Because the powers that be fear it…the only way I can buy it is in expensive pills. Ridiculous. I can be trusted to drive a car or carry a gun..but not to handle a plant?

Thank You,
Tina

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34 Green Deane May 11, 2013 at 06:36

You could grow it here in the cooler months, just don’t tell the state or they will get very upset.

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35 Keith December 10, 2013 at 21:23

Many of the best medicinal plants are made illegal. Many of the best edible plants are condemned or have been made illegal at various times. It is the nature of fascism, which is the nature of power, which is the nature of humanity, which is the nature of nature. You can remove yourself through great effort and knowledge.

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36 Sage April 17, 2014 at 22:22

Knotweed can be used to combat Lyme?? What properties? how? this would be great to know… Florida if youre struggling at all with joint pain, Teasel is miraculous. Another roadside “weed”– 2 years of Meds and I couldn’t even hold a paintbrush my pain was so bad in my hands… 1 week of Teasel and it was GONE

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37 john May 14, 2013 at 21:08

Ive heard jewelweed seeds are edible, is this true . I chewed some up last year and then spit them out because I was uncertain of their edibility they were quite tasty .

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38 Green Deane May 15, 2013 at 07:12

Read the article on jewelweed.

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39 John May 15, 2013 at 20:24

Searched articles ,can find none on jewelweed?

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40 Green Deane May 16, 2013 at 09:11

They are mentioned in the article on Edible Flowers. Jewelweed tastes bad, and requires a lot of cooking. Not a prime edible. Much over rated.

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41 Keith December 10, 2013 at 21:24

seeds are tasty IMO though i never eat many because of the less than average information on edibility.

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42 Jane Jackson June 18, 2013 at 09:59

I have just come in from taking photos of knotweed in our area. It has spread exponentially along the road side and along all the small streams that are common here.(West of Ireland). The cutting of hedges by the council is seen as the main culprit of the accelerated spread as the tiniest amount of stem can take root. It has killed off the foxgloves, primroses, wild roses, vetch, buttercups, etc,etc. that were a feature of the roadside and riverbanks in summer. It may be a good substitute for rhubarb but unfortunately rhubarb is just not that popular. I keep bees myself and a varied diet is better than a single plant that only flowers late in the season leaving the bees without any forage in these areas early in the season when they need it most for increasing there numbers.

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43 Frank Norman July 26, 2013 at 09:20

Root tincture of Japanese knotweed can be purchased and is very effective in treating Lyme disease.

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44 henry roth July 28, 2013 at 17:16

I’ve been photographing the fallen leaves and also the fallen stalks of this plant for 10 years in September and October here in Connecticut. It was just by chance that I found this site and discovered their identity! Thanks for introducing me to a fascinating plant.

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45 Marti September 7, 2013 at 18:11

It has just come up in this area of Wisconsin. But, I think it is Bohemian Knotweed. Which supposedly is a cross with Japanese and Giant knotweed. Is this also edible? I have been trying to find info on the berries, are they also useful medicinally? Cooked, sugar, or just tincture?

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46 Melissa October 9, 2013 at 00:15

We have Giant Knotweed growing in our yard. It was starting to spread, and we recently started digging and chopping it out, bagging the soil, as well, as I read that it is very easy to grow. Is the Giant Knotweed also edible? I am interested in how to prepare the roots as a resveratrol supplement. There are deep red veins in the roots. I am interested in finding out more about this plant. Can it be grown in containers and kept to a reasonable size, in order to harvest the useful parts of the plant, but not decimate native plant life?

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47 Marcela November 26, 2013 at 19:14

Giant knotweed has much less resveratrol and other stilbene contents than japanese and/or bohemian knotweeds. Dry stems of all the knotweed species are good as a fuel, for heating, of high caloric value.

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48 Keith December 10, 2013 at 21:27

look up rhizome barriers used for bamboo, no reason to believe it wouldn’t work for knotweed. however, i don’t entirely trust them to last eternity many people are comfortable using them. if not get yourself a big tupper-tub and grow them in there above ground

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49 Linda November 3, 2013 at 16:09

Unfortunately this plant is considered an extreme weed because of it’s ability to survive any thing…Deep roots help the plant to survive burning flooding…has the reputation of being impossible to kill.
Others see it as a very important medicine.
Apparently it holds large amounts of resveratrol which has successfully treated lyme disease and heart disease…The main healing properties are in the roots.
Hard plant to control though but the Japanese have used it as an extreme healing plant for centuries…

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50 frances December 4, 2013 at 01:12

it killed my diamond girl cat so its toxic to pets to eat

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51 Atommix February 4, 2014 at 07:50

Resveratrol is what this weed can do better than any other ! It makes the cells and mitochondria keep growing that’s anti ageing and can when added to red wine without the alcohol rebuild the telomer in the cells DNA ! What it does with cells is what it does as a plant it just keeps growing not good for pregnant woman unless you want a very big baby haha ! Cells are like seeds growing other cells but than they stop and die out its a bio nano program in the DNA. Combine this plant with rye grass telomersa enzymes hyluronic acid amino acids glucose and B 17 vitamins nutmeg olive oil bio oil ! And you stay young and even regenerate all your cells back to a very youth full 25 year old In one tenth of the time it took to get old ! Not bad but most people are happy to die young and let there bodies rot ? The amount of times I have had to listen to people say anti ageing reverse ageing is not for them is a reality I am most pleased with it out lines the stupid mind set of most humans and makes sure idiots don’t live very long .

And I can already hear you say prove it hahahah I can prove it but the best thing to do is try it add it all to some good collagen and exercise than look at the results in just a few weeks .. The only bad thing is some body parts never stop growing like the nose and some skin but that can be sorted out !

I am a quantum mechanic and enjoy the sound of mad people saying they couldn’t give a dam than watch them rot slowly very funny hahaha than they say they like there body rot and eat more and more rubbish talk rubbish than blossom into giant fat pigs that cant run to the toilet fast enough !

My point here is your body is a plant that needs respect just like knot-weed or it gets out of control but knot weed keeps on living and give it a chance it would take over the world ! haha ! so eat it yummy mmmmm ! but please no fats with sugars errrrr unless your a lab rat .

You probably don’t know much about cells and the flow of electrons that make the chemical reactions that make new cells and some cells are immortal so keep them in good health .. You are made of star dust super novas wow billions of years old and we are all the same age at the atomic level so just relax eat the weeds read the last page of the bible and learn that heaven will help you if you help yourself !

There is no death with the knot weed so become the weed and lets chat for a few million years hahahahha why not weed hahhahahahahah lol xxx

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52 Nicholas Taylor April 7, 2014 at 16:23

A Japanese weed-gourmet (Begin Japanology, NHK World) claims to eat deep-fried Japanese Knotweed leaves. Would this destroy the Oxalic acid?

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53 Green Deane April 7, 2014 at 22:17

I am not a chemist, but with other plants that have oxalic acid heating does not get rid of the acid.

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