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Japanese Knotweed: The Terribly Terrific Tasty Terrestrial Triffid


It really is one of those 'love, hate' relationships, depending on which side of the proverbial fence
you find yourself.

Personally, I love Japanese Knotweed. I love it's potential as a diverse food & drink resource, I'll delve deeper into that arena later. I also find it to be a striking and handsome plant.

I've read some very interesting academic, scientific and medicinal literature, both mainstream and non, which raised many a question regarding Japanese Knotweed; how it's perceived professionally, and thus culturally, and how this determines and affects it's subsequent treatment by humans. I heartily recommend the book 'The New Wild' by Fred Pearce - a book all nature lovers, conservationists and environmentalists should consider reading.

Like so many, I too was led to believe that Japanese Knotweed aka Fallopia japonica was a botanical nightmare, especially with regards to its reportedly negative impacts on our beautiful countryside, native flora, wildlife and urban dwellings, and eradication seemed the only and most sensible option. My time spent volunteering with a local council's parks and countryside's department did little to offer me, by way of alternative viewpoints regarding non-native and invasive species and the practical ways of dealing with them and, when you're in the company of qualified professionals, as someone wishing to learn more about a subject, you have less experience of than they, it's very difficult to see any other way. I'm not discrediting any of the lovely folk I worked alongside here, they too were affected by mainstream misinformation regarding the appropriate way's of dealing with non-native plants, and the rangers at that time were tremendously passionate about caring for our green spaces and the wider environment. Eventually though, I began to see and feel differently about non-native, invasive plants.

My change of heart began a few years ago when I first learned about the edibility of Japanese Knotweed (actually, changes began long before then & foraging played a major role in that change). After spending more time in the presence of this plant, observing it, eating, drinking it and developing a deeper revulsion toward poisonous chemicals being employed in attempts to eradicate it, a practice I've disliked for many years, I started to feel that something wasn't quite right with our mainstream perceptions of and dealings with it. Discussions with various folk who had a more positive outlook; other foragers, medical herbalists and environmentalists, also played their part in facilitating my change of heart.
I hope this article and its content will go someway to facilitating a change of heart and also in our collective, cultural perceptions. 

I will provide a number of links at the end of this article for reference and further reading.

How Did It Get Here?

Fallopia japonica, aka Japanese Knotweed, was introduced to the UK by the Victorians and it was first housed at Kew Royal Botanical Gardens circa 1850. It was famed and desired for it's attractive flowers and how the stems resembled bamboo. It quickly became one of the eras 'must haves' for budding gardeners and plant enthusiasts, a kind of Victorian 'keeping up with the Jones'' or more appropriately, in those days 'keeping up with the De Veres darling'.
Unknown at that time was the plants propensity to vigorously and rapidly grow, which it did.

A Misguided History

Left unchecked, this tough and adaptable plant can appear to run amok, choking vast swathes of water system banking's, roadside verges, gardens and fields, and due to this it quickly became arch-enemy number 1 of the plant kingdom. Modern economics played a major role in the vilification of this quite remarkable plant, particularly where the building industry was concerned - it's ironic and distasteful how the acquisition and development of our green spaces for housing, industry, infrastructure hardly raises so much as an eyebrow, yet the potential harm to those buildings, in economic terms, creates hysteria... Banks, building societies and insurance companies, spurred on by misinformation and misunderstanding, also got their knickers in a twist. This in turn affected the general public, especially those being refused mortgages. The all pervasive negativity surrounding Japanese Knotweed fueled the need for a solution to the problem, and unfortunately, when humans and nature collide, nature generally suffers: seeds of hatred are sown, germinate vigorously and flourish rampantly. The anthropocentric superiority-over-nature-complex further exacerbated negative views and practices, and sadly, eradication/removal via the use of poisonous chemicals became the norm: the war against JK was on.

The Problem With Poisonous Chemicals

As mentioned earlier, I have a deep revulsion concerning the administering of poisonous chemicals. Poisonous chemicals affect not only the plants/insects/fungi they are designed to eliminate but they affect wider human and environmental health, impacting the very fabric of our ecosystems: anyone that is under the illusion that these chemicals merely vanish without a trace are indeed ill-educated and thoroughly disillusioned. Toxins are washed and leached into the fresh water systems; this is basic science. They then work their way into the bodies and cells of living organisms and work their way up and through the food chain via those living organisms being consumed by other living organisms - again, basic science. Soil health too is compromised and I'm genuinely shocked at how unaware most humans are regarding soil: take a look around at the land and observe what grows from soil. Soil health should be taught as part of the national curriculum. Please don't be angry at what I'm writing, I too spent many years unaware or in ignorance of theses issues until I informed myself otherwise.

At this point some of you may be saying 'but chemicals are a part of the natural world' and this is true, there are a multitude of chemical processes at work daily in the natural world, ants spray formic acid to ward off predators, certain carnivorous plants give off chemicals to attract their prey, but those chemical processes are natural and limited in their wider effects. They are not man-made and they are not designed to be profited from at the expense of environmental/ecosystem damage, destruction and health. There has recently been a very interesting court case in the US involving a certain corporation; they have been found guilty of deceit, lies and of misinforming us about one of their products called Roundup. Roundup is a weedkiller that contains glyphosate and it has been proven to be highly carcinogenic - cancer causing - among other health compromising issues. So, all you budding gardeners, council department and farmers currently administering glyphosate containing, chemical nasties to treat Knotweed, other 'weeds' and foods (wheat in particular) please put away your chemical weapons, engage with the science, and for goodness sake, start apply some basic common sense. Cleaner, greener, non-polluting alternatives are available and the future health of our children and the environment at large depend on these.

Alternatives To Chemical Treatment


Knotweed Shoots & Old Woody Stems
Alternative methods of management and treatment are currently and actively being adopted and trialed such as electric shock treatment of the roots. There is anecdotal evidence which claims the continuous harvesting of the young shoots actively weakens the root stock by negating the plants ability to grow leaves and therefore photosynthesize; again, basic and obvious science/common sense. If a plant that depends on photosynthesis is unable to do so, it will not be able to store nutrients in its roots, weakening the plant and eventually killing it off. There is also anecdotal evidence that certain, naturally forming plant chemicals, such as those given off by Garlic Mustard (Alliaria petiolata) inhibit the growth of Japanese Knotweed, this info comes from @thallifoods on Instagram, check out their instagram feed for more info.

To date there is no conclusive evidence to prove either of the above, but they both make a lot of sense and a thorough, long-term, strategic experiments require initiating, complete with transparent, unbiased, detailed documentation and reports. If these techniques are indeed proved to be correct, employment opportunities will be created through the annual harvesting, processing and sale of nutritious food, drink and medicines. I'm pretty sure that the dried out, woody stems could be used as a biofuel or compostable packaging - Knotweed only regenerates via sections of root.

The best recipe for dealing with JK in my mind is one for Knotweed Ketchup, but more on that later.

Good News For Home Owners

Fortunately, thanks to recent scientific and academic research, obtaining mortgages on properties with Japanese Knotweed in the nearby vicinity are being granted. It seems that JK's rumoured tendencies to smash down and through buildings like some bad tempered, hormonal and testosterone-fuelled, teenage Godzilla punching it's way through wet tissue paper is utter hyperbole, as this recent research paper by Leeds University explores:
https://www.leeds.ac.uk/news/article/4262/japanese_knotweed-not_such_a_knotty_problem

Why Pick Japanese Knotweed? 

More to the point why not? Japanese Knotweed is a member of the polygonaceae family, the exact same family as rhubarb and as such is as culinarily versatile as rhubarb. Other family members include; common sorrel, bistort and dock, all of which are edible and tasty to varying degrees. JK is also classed as a non-native, invasive species and grows at a remarkable rate so, gathering for cooking purposes isn't an issue, it would only be an issue if it were a rare, at risk species. JK has been awarded the more pleasing name 'Asian Rhubarb', I also like to call it 'Wild Rhubarb'.


What Can You Make With It?

What can't you make with it? Well, you can't make it rain but that's not usually an issue in the UK.

More and more folk are tuning into this amazing plant, thanks to forward & progressive thinking environmentalists and culinary-creative foragers and chefs; once reviled, it is gradually becoming revered!  The solution, or at least one solution, is to ensure we don't leave it unchecked; it's time to rescue it, the environment and public health from it's current misconceived reputation and toxic-eradication-shackles and put Japanese Knotweed firmly on the menu.

To date I've made no less than 18 different food and drink products from Japanese Knotweed and there's scope for more:

1.  Japanese Knotweed Wine - works well with Sweet Cicely added.
2.  Japanese Knotweed & Sweet Cicely Chutney.
3.  Japanese Knotweed & Sweet Cicely Liqueur.
4.  Japanese Knotweed & Star Anise Jelly.
5.  Japanese Knotweed Ketchup - several variations, all excellent.
6.  Japanese Knotweed Curd
7.  Japanese Knotweed Ice Cream w/ Lime, Vanilla & Mixed Spice
8.  Japanese Knotweed Fruit Leather
9.  Japanese Knotweed & Birch Syrup Puree - great w/ vanilla yogurt & pepperkakor crumb
10. Japanese Knotweed Syrup
11. Sweet Pickled Japanese Knotweed Sections - several spice blend variations in the pickling liquor
12. Candied Knotweed
13. Japanese Knotweed Crumble
14. Fermented Knotweed.
15. Pure Juice - great added to cocktails to sour them
16. Japanese Knotweed Cordial
17. Japanese Knotweed & Sweet Woodruff Tarts
18. Japanese Knotweed & 3 Cornered Leek lacto-ferment

Not a bad repertoire for such a destructive weed. Btw, the hollow stem sections also make great drinking straws.

Knotweed & Sweet Woodruff Tarts
Knotweed Jelly w/ Star Anise












For more Japanese Knotweed Recipes: https://edible-leeds.blogspot.com/2019/04/japanese-knotweed-recipes.html

Medicinal & Health Benefits

Aside from food & drink, JK has numerous medicinal qualities. The roots provide a source of resveratrol and that is extremely effective at combating Lyme Disease. The following link lists some of the health benefits from eating Japanese Knotweed: https://www.organicfacts.net/health-benefits/herbs-and-spices/japanese-knotweed.html

Wise Foraging, Preparation & Disposal Methods

If you are intending to go out and pick Japanese Knotweed you need to ensure that the site you're gathering from hasn't be treated with chemicals. Signs to look for are withered or damaged leaves on plants near where you are collecting. This isn't always an adequate safety precaution as chemicals may have been injected directly into the plants stem base, close to the root, despite the industry claiming this isn't a 100% sure fire way of killing the plant - so why bother? Look for dark blue liquid staining on the plants stems, again, great if it's been recently treated. You can contact your local council and ask where treatment of known Japanese Knotweed sites are, you can also contact them to complain about the administering of poisonous chemicals and the harm to human, aquatic and environmental health.

It is an offence to knowingly cause the spread of Japanese Knotweed and you can be prosecuted if you do so. Knotweed will only regenerate from sections of root but you will be harvesting the young stems, so shouldn't have any root attached.
If you have any leftover sections after preparing Japanese Knotweed ie leaves, stem sections, boil them for 10 minutes. Further advice recommends the drying and incinerating of the boiled sections. Personally I find this a bit overkill, try boiling a potato, planting it and see if any new potatoes grow from it. Following the advice provided regarding the discarding of unused parts is best adhered to, just to be on the safe side.

Nature isn't our enemy, it is our friend. A healthy environment will provide us with the necessities required for a happy and thriving existence. if it wasn't for nature, we/you wouldn't be here. It's time to restore our vital connection with the natural world, our life support system.


Links to references and further reading:
https://usrtk.org/monsanto-roundup-trial-tracker-index/
https://www.theguardian.com/business/2018/aug/10/monsanto-trial-cancer-dewayne-johnson-ruling


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