Japanese Knotweed – Friend or Foe?

Japanese Knotweed

We all know Japanese Knotweed (Latin names include: Polygonum cuspidatum; Reynoutria japonica; Fallopia japonica) as an invasive and prolific plant that is creating problems wherever it grows.

It is a native plant of the Far East and was brought to Britain in the 19th Century primarily as a fodder plant, an ornamental and for erosion control. Since then, it has spread throughout the Western world and ranges from small isolated clumps to spreading forests of many acres. In fact, outside it’s native range, the University of Leicester has identified the plant as a cloned female and it is thought that it is the biggest female organism in the World!

Here’s a slightly different look on what this plant can be rather than the scourge it has been labelled, but I shall treat it like we do any other plant in our expanding repertoire of plant knowledge.

WARNING: This plant is classed as a major problem within the UK. You could be fined up to £5,000 or be sent to prison for up to 2 years if you allow contaminated soil or plant material to spread into the wild.

Please refer to GOV.UK and The Environment Agency for more information.

Food uses
Japanese Knotweed is not generally considered a food within the UK due to the rules and regulations regarding the spread and possible problems this plant may cause. However, throughout it’s range in the Far East and even through the USA it is a recognised food source (with a sneaky following in UK).

The best time to eat Japanese Knotweed is when it is just putting out its shoots, up to about 20cm in length. After that, they can get a bit stringy but as long as the stem feels ‘juicy’ it can be cooked and eaten.

The plant is rich in Vitamins C and A, tastes a little bit like a less tart rhubarb and the shoots can be can be cooked like asparagus, the stems can sliced and put in to crumbles, added to muffins, use as a replacement for celery for dipping when you host those posh dinner parties or split and stuff with cream cheese (or peanut butter) and sprinkle dried fruit and/or nuts on the top.

For those of us who booze forage, you can make Knotweed vodka.

In the Far East and the USA, it seems the thinking is ‘If you can’t eradicate it, eat it.’

Another word of warning though – There have been incidences of sensitivity to the plant similar to those seen from hogweed.

Japanese Knotweed anyone?
Japanese Knotweed anyone?

Non-Food uses
Similar to Rosebay Willowherb, Japanese Knotweed is a pioneer species and able to rapidly populate disturbed land. One of the local names for this plant is ‘Volcano weed’ as it turns up around areas of recent volcanic activity (rather like the way Willowherb is known as ‘Fire weed’). With that ability and its tolerance of a wide range of soil pH, it has been used as a method of soil amelioration on contaminated land. Some research is also being done as to its potential use as a biofuel.

The plant is a good nectar producer so is an attractive and useful plant for bees and other insects.

As a plant dye, it gives a plum to rose-gold colour to fabrics.

Medicinal uses – now we’re talking!
Japanese Knotweed has been used in Oriental medicine for a few hundred years in various forms of preparation for the treatment of such diverse ailments as sore throats, wounds and burns, arthritis, coughs and the production of phlegm, menstruation problems and even snake bites!

It’s like the ‘Plantain of the East’.

Furthermore, it has the highest level of plant resveratrol, a compound found in red grapes, blueberries, peanuts and mulberries that is reputed to have antioxidant and anti-aging properties, among other things.

Japanese Knotweed - the science
Japanese Knotweed – the science

And there’s more…
Scientific research is being carried out with Japanese Knotweed for the treatment of Lyme disease.

Yes, you read it right…

 …the treatment of Lyme disease.

As this is only a quick blog and therefore a ‘taster’ for you, the reader, to go out and expand your knowledge as you feel the need, I won’t go in to the scientific stuff. Suffice to say that Japanese Knotweed is becoming one of the most important plants in the treatment of Lyme disease and has shown to specifically address the nervous system and neurological complications as well as killing the Borrelia bacterium bacteria itself.

John Hopkins University
Saltwire Network
Practical Self Reliance.com
The Other Andy Hamilton

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