Japanese knotweed leaves chopping board

Is Japanese knotweed safe to eat?

When you hear of all the horror stories in the press about knotweed it is easy to believe that it’s a dangerous hazard. Pictures of knotweed growing through cracks in concrete, taking over people’s gardens and generally causing a nuisance, are all over the internet. The word ‘triffid’ is never far from people’s lips when they talk about the plant. Consequently, there are many who believe it to be a harmful species, rendering their house unsellable. 

Nothing could be further from the truth.

Japanese knotweed does not sting people, feed on their corpses and walk around of its own accord, so the triffid comparison is somewhat unfounded and wholly unfair. It is completely safe to touch and is, in fact, edible. With a taste reminiscent of a lemony rhubarb, Japanese knotweed features in a whole variety of both sweet and savoury recipes, including purees, jams, sauces, fruit compotes, soups, wines and ice creams to name but a few. Take a look on Pinterest - there are numerous boards here with suggestions on what you could do with knotweed in the kitchen. The variety shows just what can be done with a bit of imagination! Maybe we’ll try out a few recipes for ourselves and report back in a future blog. 

Not only is it edible; it is good for you. Japanese knotweed is an excellent source of Vitamins A and C and contains potassium, zinc, phosphorus and manganese. It has been used for centuries in its native countries for treating many ailments, such as respiratory infections. Knotweed also contains amounts of resveratrol, which can be used to reduce cholesterol (although large quantities would need to be consumed to get these benefits).  So the plant is not quite as bad as the press would have you believe. 

One of our directors visited a Vietnamese restaurant in Shoreditch last year, and enjoyed amongst other things a delicious knotweed Noodle dish. They were queuing down the road to get a table - word must have got out that knotweed was on the menu!

So, with all these health benefits, is the answer to the Japanese knotweed problem: go out and eat it all?

Well, no. 

To begin with, not all parts of the plant are edible (as with rhubarb) and they are only edible at a certain time of the year. The shoots in the spring are tender enough to eat, but they have to be gathered before the stems become hard and woody. The ideal time to eat knotweed is mid-April to May. With only part of the plant being used this leaves the rest of the knotweed in situ to continue growing.  It is also important to note that removing knotweed from its site of origin without taking it to a registered landfill,  is against the law and could leave you open to prosecution by the Environment Agency.

There is one other consideration. Awareness of knotweed is now so high; would you be able to guarantee the knotweed you are about to eat has never been treated with some form of herbicide in the past? 

Can you eat Japanese knotweed? Yes you can. Should you? Maybe not. Eating the knotweed will not eradicate the plant, as the underground root system will still be intact. If you don’t fancy knotweed for dinner and would like to have it professionally removed, please get in touch. We have a variety of Japanese knotweed removal techniques suitable for all jobs. 

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