Monday, April 25, 2011

Eating Japanese knotweed

Prehistoric-looking Japanese knotweed growing in Manhattan. I believe that at this stage you actually watch it grow. Ellen Zachos hunted it in the same spot early in the week and I found it on that week's Friday, this tall, up to two feet.

I picked a paper bagful and promised Vince that I would wash it very, very well. Which I did, after grading it into different sizes. I had never cooked with it and wasn't entirely sure where to begin. Ellen, my foraging guru,  had prepared some out in Pennsylvania, when I visited last fall, gratinated with parmesan cheese. It was very good, like super-soft and slightly astringent asparagus. Her knotweed wine ish wunnerful.

My reading indicated that it would be tart, and that it might be fibrous. My stalks ranged from 6" to 16", and I wondered whether to peel the very thin, red-freckled skin from the outside. In the end I did just that, worried about stringy bits, and it took a good hour to wash and clean the whole collection. Then I bagged it in batches and kept it in the fridge. We ate the last pieces last night, sliced raw into thin rounds in a  green salad,  and they were still very fresh and crisp, eight days later, so it keeps exceptionally well.

Various sources said that the leaves would be tough but the tips looked so good to me that I tested a few, boiling them till just cooked. Very soft and tender, slightly sour, with perhaps an almost imperceptible squeak in the texture. We ate them all as a side to roast chicken.

Up next, risotto. Lemon risotto is delicious, and I thought that the knotweed would meet the sour requirement nicely. Diced small and blanched, I added it in the final fifteen minutes of cooking. The Frenchman's verdict? More!

Lamb pot roast. We ate it too quickly for a picture. The knotweed melted into the pot juices until it had formed a creamy sauce with the Sylvaner I had added, and met the sweetness of the carrot and celery perfectly, with a background bite of sourness.

We eat veal once every four blue moons for obvious reasons, and this time I riffed on the theme of blanquette de veau, with mushrooms, knotweed and thyme. And cream. The knotweed practically dissolved and some complexity to the famous creaminess of the dish. This was pretty good.

And finally...dessert! 

Knotweed is described as being similar to rhubarb, and I'd read about knotweed pies, so I thought perhaps I could add it, after cooking in sugar syrup, to the custard of crème brûlée. It was fine. The custard was quite lovely, but the knotweed was a total distraction. I was trying to be too clever. I don't want anything in my crème brûlée, except crème.

What a wonderful plant, how very versatile in the kitchen and how sad that is it ready but once a year. Or perhaps that is its charm. It is very good for us, loaded with vitamin C and resveratrol, and I would love to eat it more often.

If you'd like to learn more about knotweed, read my article on this eminently edible invasive weed in Edible Manhattan

2012 update:

Knotweed and roast lamb
Knotweed curry
Knotweed soup


  1. I'm stunned. This stuff is the bane of my urban garden. I had no idea it was edible. You're very adventurous!

  2. A few ideas for your new NYC Knotweed resto ("Knotty-but-Nice"?):
    -Knotted Cream – Like clotted cream but without the hypertensive properties
    -Knottage Cheese – Side dish for dieters
    -Knot Roast – Self-explanatory
    -Knotcakes – A little like hotcakes, a little like crepes, but twistier
    -Knot-de-crème – Tres français mocha-chocolate dessert, vegetarian version
    -Knot Toddy – Best served in winter or early spring when the fixings are just shooting forth

  3. Marie, great post! You're fast becoming quite the urban forager.

  4. You learn something every day! I didn't know you could eat it!

    Here in England, we have to notify the authorities if we find any Japanese Knotweed. I don't know what they then do, maybe send the armed forces in!

    Another recipe;

    Knot Dogs, weed served in a bun with the usual accompaniments!

  5. Good heavens. This plant has been so thick on the ground up here -- and for my whole life -- I thought it was some kind of native plant. We made flutes out of it (not very successfully, but it passed the time on lazy days).

  6. When we bought our house in NJ five years ago we inherited a big patch of this in the back border. After lots of digging it out and strategic use of glyphosphate, it still comes back every spring in tiny spots here and there. I have that same feeling of "Really? Again?" when I see its little shoots. It's like a horror movie. I've realized that I may never truly eliminate it from the garden but have learned to "manage" it, like arthritis or something. I don't think I could eat it after so much ill will towards it.

  7. I suspect it was its edibility as well as its decent looks that has made it so successful. I do wonder if you made all those dishes on different days!

    Reversatrol? That's how I read it. Whatever it is, I need me some reversatrol.

  8. Urban Cottage - I'm just hungry :-)

    Janet and Anne - knot dogs, knot roast - you guys need to do stand up botanical comedy! Badabing!

    Thanks Thomas. Yeah, funny, I've always liked to eat wild things and never knew until about a year ago that it had a name!

    Melanie, I could see how it would make flutes. Or be an airtube for underwater swimming...sneaking up on ducks.

    Brian - aw, go on...Have a nibble!

    Frank, reversatrol, now that would be valuable... sigh.

  9. Hi Marie, interesting post, I didn't realise it could be eaten. A friend of mine had it in their garden and ended up pulling the roots out by tractor, they go incredibly deep. She should have grazed them instead!

  10. Wow what a fantastic menu! I am SO going to try your risotto idea.

  11. The knotweed risotto sounds very good. As kids, we used the hollow dried tubes to make dart guns and spitball tubes. Now, we eat them as well, although our season for tender stalks is almost gone by . .

  12. Japanese knotweed is a bit of a tricky one, certainly delicious so long as it can be controlled, but picking it as soon as it starts growing is certainly one way to manage that.


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