Spring green

Pick your own knotweed shoots

By
April 2, 2008

My friend Leda and I are partners in crime. We conspire to pick noxious weeds in a public park, which, technically, is against the law. I checked. The fine in New York City is $1,000 for removing plants from a park, although writing a ticket for picking an invasive plant like Japanese knotweed should make any self-respecting park ranger blush. When I weigh the tart, zesty taste of knotweed shoots against the threat of a hefty citation, the scales tip heavily in favor of the knotweed.

In the spring, Japanese knotweed sends up thick green spears mottled with red, like asparagus on steroids with a sunburn. Exactly when it muscles its way up through the earth depends on where you live. In New York City, the knotweed picking is best in April, so harvest earlier if you live farther south, later if farther north.

Knotweed stalks at prime harvest time.

Before it starts to branch, knotweed is very tender; after branching, the stems are so tough that you have to peel them to eat them. That’s too much work for me, so I harvest early. Knotweed grows fast; within a few days, it’s gone from tender to tough, so when I see the first spears poke up, I don’t dawdle.

Some people think knotweed is bamboo, because of its tall, woody, jointed stems. It’s not closely related, but it’s just as invasive; by the end of summer, knotweed can be six to eight feet tall. The tall, dead stalks from the previous year’s growth make excellent markers for new growth in the spring, with the young shoots poking up around the old stalks.

On a fine April day, Leda and I saunter into the wilds of Manhattan’s Central Park. Our innocent-looking tote bags conceal not-so-innocent-looking bypass pruners. We know where the knotweed grows. Actually, knotweed grows almost everywhere, but in Central Park it’s most abundant in the Ramble, near the lake. And since the terrain is less inviting there (unless you’re cruising for a special kind of companionship), there are fewer meddlesome tourists and birdwatchers with binoculars.

Harvesting with Leda is great for many reasons. First, there’s the traditional camaraderie that comes from foraging; the quiet walking, the easy chitchat. Second, two pairs of eyes are better than one; one person can look out for park rangers with quotas to fill while the other harvests. And third, casual conversation is a surprisingly effective camouflage. There is no furtiveness here, no stealing under cover of silence. We are just two harmless women doing something confusing but clearly entirely legal. In the wild, conversation offers the additional protection of letting the wildlife know you’re coming, allowing it to make an unpanicked retreat. In Central Park, it takes a little more to drive off the wild beasts.

A mature knotweed plant is essentially a large shrub.

Japanese knotweed (aka Polygonatum cuspidatum aka Fallopia japonica) grows in sun or shade, in roadside ditches, on steep embankments, on boggy islands, and in Central Park. It was touted in the 1970s and 1980s as a quick-growing plant, useful for stabilizing eroding roadsides and creating windbreaks and living fences. Too late, environmentalists realized someone had made a big mistake. In the U.K. it’s now illegal to plant knotweed anywhere, and parts of the U.S. are following suit. Knotweed produces thousands of seeds per plant, and it also spreads by underground stolons. In Darwinian terms, it’s a very fit plant.

So in an effort to save the world, or at least a little piece of it, let’s all do our part and pull up as much Japanese knotweed as possible. Choose unbranched spears, between eight and 16 inches tall. They may be as thick as your thumb or as slim as a pencil. Sometimes you can snap them off at ground level, but a pair of pruners speeds the harvest. In less than half an hour you can easily pick five or six pounds of knotweed, enough for a batch of wine, some soup, and a couple of stir-fries.

Since there are so many things you can make with knotweed, you’ll have no trouble using as much as you harvest. And if you clean and freeze the stems when you get home, you can cook with it at your leisure; it keeps for months in the freezer. Knotweed wine is one of my favorite home brews; it takes less time to finish fermenting than many other wines and tastes like a good sauterne with a tawny gold color. Knotweed can be substituted for rhubarb in pies, jams, and jellies; it combines well with strawberries, blueberries, and apples. And, yes, you can use knotweed as a vegetable; it’s tart and crunchy in stir-fries and lemony delicious under hollandaise. My favorite way to eat knotweed is in a creamy soup. Nothing like turning environmental activism into lunch.

The park rangers haven’t caught us yet, nor has the local wildlife, human or otherwise. And the occasional birdwatching tourist usually moves along if Leda and I babble to each other in Greek. As for the average New Yorker, it takes a lot more than two women with bags full of knotweed to make one stop and stare. Unless it’s another enlightened forager; then we nod, smile, and continue with our rite of spring.

The author of Down and Dirty: 43 Fun & Funky First-Time Projects & Activities to Get You Gardening, Ellen Zachos is a former Broadway performer who recently recorded Green Up Time: A Botanical Look at Broadway, a CD that combines her two passions: music and plants.

Correction: As noted in the comments below, the scientific name of knotweed is actually Polygonum cuspidatum.

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1. by ledamer on Apr 2, 2008 at 12:51 PM PDT

Makes me hungry for our upcoming knotweed excursion!
Leda

2. by acmeplant on Apr 2, 2008 at 5:18 PM PDT

Don’t forget to wear camouflage!

3. by Kelly Myers on Apr 5, 2008 at 6:52 AM PDT

Amazing. I have spent years eradicating knotweed, which originated in the yard of our neighbor, an absentee landlord. At one point it was about 15 feet tall. Years later, the occasional stolon still sends up a shoot. I am always on the lookout for them. Now I’ll know not to throw them in Metro’s yard debris bin. Thanks.

4. by TheJewAndTheCarrot on Apr 7, 2008 at 9:15 AM PDT

Great post! It was so funny to read this on Culinate today b/c my boyfriend and I JUST went on a foraging tour yesterday with foraging guru, “Wild Man Steve Brill” (who did, indeed get arrested for foraging). We picked all sorts of yummy things - the best were wild bay leaves and field garlic, which we used in a pasta dish that night.

Check it out here - and keep on foraging!

http://jcarrot.org/foraging-is-the-new-local/

5. by Maman on Apr 7, 2008 at 5:53 PM PDT

That stuff is edible? I have been trying (unsuccessfully) to kill it for years in my backyard!

6. by anonymous on Apr 9, 2008 at 8:27 AM PDT

Hi, not to be picky, but it should be Polygonum.
Polygonatum is Solomons Seal. Great article! I love Japanese knotweed!

7. by acmeplant on Apr 13, 2008 at 3:14 PM PDT

Oh you are so right! I apologize. It’s Polygonum cuspidatum. Good catch.

8. by Keith Morris on Apr 26, 2008 at 3:58 PM PDT

Great article... there just now coming up here in VT. I’ve always just done the ‘asparagus’ thing. Any way to get your wine recipe?
Thanks,
Keith
earthsurfing(at)yahoo.com

9. by acmeplant on Apr 26, 2008 at 4:23 PM PDT

Glad you saw the article in time. You can harvest now, chop and freeze the knotweed, and make the wine whenever you have time. The recipe below assumes you have some experience with wine making. If you don’t, you’ll need to look up some basic info. This is adapted from a rhubarb wine recipe. Good luck!

Knotweed Wine
Roughly chop 3 lbs. of knotweed and combine with 8 oz. chopped raisins in a fermentation bucket. Crush lightly, then cover with a syrup made from 3 quarts of water and 2.5 lbs. sugar. Add a tsp. orange zest, 1/4 tsp. tannin powder, and a crushed Campden tablet. Stir, cover, and leave for 24 hours. Next, add 1/2 cup orange juice, 10 drops pectic enzyme, 1 packet wine yeast, and 1 tsp. yeast nutrient. Leave the mixture covered for 10 days, stirring daily. Strain the liquid into a one gallon, glass jug. Rack off the lees as needed. Bottle when clear, and drink after 1 year (from starting the brew).

10. by Joseph Sikorski on May 11, 2008 at 3:25 PM PDT

Wow! This was posted pretty recently!

Here in New Jersey, there’s also a lot. Right out back, in fact, it’s all down the river side! Anyway, we’ve been playing around with cooking it mostly into puddings, but sometimes sample it raw. It’s a bit sour, though...

I’ve found that even on the taller plants, if you test each section, you can get a good usable portion. I start close to the bottom, give it a good yank, then then proceed to the next one up until it just pops off with out any little fibres sticking out. The little branches are pretty usable, too, though not as nice to just chew. Basically, though, the higher up parts are like the fresh shoots. So, there’s even less a “shortage”. The smaller ones are just easier to pluck whole, I think. :)

Actually saw this a little earlier (You must have just posted it, then!), but didn’t notice the date or play around any weeds as much, yet. So thanks for helping send us off on new little adventures! We’re gonna see if we can’t get more people doing this...

11. by acmeplant on May 11, 2008 at 4:51 PM PDT

Hi Joseph, I’d love to have your pudding recipe if you want to share.

I agree w/you about the tops of the plants sometimes being usable. When Leda and I went gathering this year we found lots of tender tops, which made it very easy to fill our quotas.

12. by Joseph Sikorski on May 31, 2008 at 9:42 PM PDT

Haaaaaaaaaaaah, totally late. Sorry about that. I’m sure you’ve found plenty of ways to play with knotweed. Anyway, I didn’t keep the pudding recipe, but I think if you just stop after at the egg yolks here, you’ll get it. It’s a simple pudding, after all. This frozen pie recipe is adapted from the frozen keylime pie in The Art of Desert.

Day One :
– Ingredients –
• 3 cup diced knotweed
• 1/3 cup sugar
• about 1/4 cup water
– Directions –
• Simmer 20 minutes
• Allow to cool
• Liquify in blender to consistency of pudding
• Refrigerate over night
(This actually made more than was used below... We’ll use it in something...)

• Also, on day one, make a graham cracker crust in a pie pan and freeze.

Day Two :
This is basically a frozen pie thing straight out of a cook book. Lime juice and zests substituted with knotweed stuff, though.
– Ingredients –
• 5 eggs, separated
• 2/3 cup knotweed stuff from above
• 1 cup heavy whipping cream
• 1/2 cup sugar (For the yolks)
• 1/4 cup sugar (For the whites)
– Directions –
• Whisk yolks, slowly adding 1/2 cup sugar, till thick and pale.
• Stir in 2/3 cup knotweed stuff.
• Cook on medium for a little while. About 2 minutes, stirring constantly to avoid scorching
Originally said “Until coats back of spoon and line stays.”, but this is knotweed stuff, not limewater...
• Cool to room temp.

• Whip the cream to stiff peaks
• Refrigerate

• Whisk whites until foamy, slowly adding 1/4 cup sugar.
• Beat to stiff glossy peaks

• Fold whites into yolk mixture, all at once.
• Fold in the whipped cream.
• Pour into frozen graham cracker crust.
• Freeze uncovered for 3+ hours.

13. by acmeplant on Jun 3, 2008 at 6:05 PM PDT

Thanks so much Joseph! You’re not too late at all. I have company coming this weekend for a foraged feast and I wanted to make an interesting desert. I’ll use the knotweed I froze earlier this spring.

14. by alemarch on Jul 7, 2008 at 2:08 PM PDT

This is great! The more I research, the more I find out that my yard is a treasure trove of food. We have a fairly big stand of knotweed that I’ve avoided doing anything about until I knew more about it. Sure am glad I waited. Now all I have to do is wait until next spring. Dang.

15. by acmeplant on Jul 7, 2008 at 2:29 PM PDT

Good thing you waited. Too many people pull out the Round-Up before they really understand what they’re dealing with. Your patience will be rewarded!

16. by TJ on May 12, 2009 at 9:17 PM PDT

I was looking up knotwood because it was an ingredient in a diet drink I saw. This has interested me so much. I am from New Mexico, USA. Do you think I could actually plant this in my yard? If anyone has a way to get a hold of seed or plants, please let me know.

17. by acmeplant on May 13, 2009 at 4:20 AM PDT

Hi TJ, I’m curious, which diet drink lists knotweed as an ingredient? I think it’s great that someone is using the plant commercially. As for planting it yourself...I’ve never seen either seeds or plants for sale, probably because it’s so rabidly invasive. You could probably dig up some young plants and transplant them, but I’d think about this long and hard before doing it.

18. by TJ on May 18, 2009 at 4:10 PM PDT

To acmeplant re: your e-mail. I found Japanese Knotweed extract as an ingredient in SLIMQUICK powder. The one you mix in a water bottle. Thank for answering my question so quickly. I will keep checking back periodically.

19. by Japanese knotweed on Jul 9, 2010 at 1:40 AM PDT

Wow what a great insight to the process of eradicating japanese knotweed. TJ - i’m not sure where you are from but I know in England it is not a good idea to want to plant this weed.

Make sure you fully research everything before doing anything drastic.

Thanks for the post

20. by Karen on May 4, 2011 at 12:24 PM PDT

Good post, hope you get out every year to get more. We also have some knotweed recipes posted, mostly for desserts and a jelly:

http://the3foragers.blogspot.com/

21. by TJ on May 4, 2011 at 6:38 PM PDT

Thanks for the e-mail. Recipes sound great.

22. by Keith on May 4, 2011 at 7:18 PM PDT

My favorite recipe to date-

Cut knotweed into little slices (they’ll look like little ‘rings’.

Cook a can of Tomato Soup.

Drop in knotweed.

Drop in a whole brick of Cream Cheese.

Simmer until Cream Cheese is totally melted/ mixed in and knotweed is cooked.

YUM!

23. by anonymous on May 16, 2011 at 11:43 AM PDT

I’m trying to eradicate these things from my backyard. Maybe I’ll give cooking them a try in the process. Thanks

24. by anonymous on May 13, 2012 at 6:57 AM PDT

While I encourage anyone and everyone to eat this plant, I cannot caution you enough....DO NOT PLANT THIS THING ANYWHERE!! It is a powerful invasive, and it will outrun any effort to contain it. It is resistant to decades of mowing and gallons of poison.

25. by Bernie on Jun 24, 2013 at 10:51 AM PDT

OH MY GOD! You - and that means ANYONE - should contact me in the spring, honey. I have the patch of knotweed FROM HELL and have done all that I can to keep it from eating me alive. There’s so much of it that I could be a knotweed purveyor for everyone in the U.S. with an endless supply. I’m always trying to figure out ways to SUPPRESS it, but anyone who knows knotweed knows that it’s just about impossible..without suppressing everything for a couple of years. I never use chemicals, just cutting and stomping it, so I am guilty of years of trying to (s)quash the very thing I should have been eating. Next spring - ABONDANZA!!! I need help - come on over, knotweedophiles!!

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