Tag Archives: Japanese knotweed

365 day 102 Sarphatipark

Thanks to the watertolerant group who joined me to herb walk in Sarphatipark today. We found lots of useful herbs and also interesting park workers who told us how the park is maintained by a dynamic group of volunteers and is trying innovative edible approaches to eradicate Japanese knotweed. Above is a park warden, pictured by the enormous Jerusalem artichokes which are being used to keep knotweed at bay. When the invasive plant is removed, the ground can quickly turn into a home for other unwelcome invaders or can see the return of knotweed. Using Jerusalem artichoke, another rapidly growing and spreading plant, can provide tasty tubers and quash the knotweed. So far so good!

I was also reassured to learn that the Ginkgo trees I’m so fond of in parts of Our Zuid are indeed female and yield plentiful Ginkgo nuts. Amsterdam is fortunate to have such edible plant loving folk in its green spaces team.


The plants I remember finding today are listed as tags to this entry. The spreading soft leaved plant which looked quite like Agrimony but wasn’t, was indeed a cinqefoil, called Silverweed previously called (Potentilla anserina) but now reclassified as Argentina anserina . It is shown above and it is edible. If you were on the walk and can remember other plants which I have missed from the tag list then please let me know.

Thanks again to everyone who joined me. It was a real pleasure to walk around with you. If you signed up but were not brave enough for the wet weather, remember there are always trees to shelter under next time 🙂

365 Frankendael day 20

Day 20 of the project and after going to the park expecting to see just one or two new things I was delighted to find my first Elder blossom of the season, Wild Aspraragus shoots and several other delights. Here are a few…


Above, Japanese knotweed is still fair game for Foragers looking for something a little exotic in Amsterdam. Here’s a link to my
sweet sour JKW yoghurt recipe

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Next is A Geranium species in flower. Very tasty cooked or raw.


Someone got to this Asparagus before me. It makes a stunning tall feathery plant when allowed to flower. I hope that whoever harvests this one leaves some other shoots to flower and fruit unhindered.


Above is Plantago major (NL: Wegbrood, Plantain) in full effect, prior to flowering. It’s not as useful a medicinal than its slender sister Ribwort (Plantago lanceolota) but its useful and quite good eating.

I feel like a bird spotter with this one… Above is my first sighted Elder blossom of 2012 and it gets me very excited. Elderflower fritters, Elderflower champagne, Elderflower tea and a host of other flower and Elderberry recipes are not far away! This huge Elder shrub is on the Middenweg, just up from the top entrance of Frankendael and opposite the Vomar supermarket. If only my arms were long enough! Remember to harvest with respect and leave LOTS for the birds and bees. Also be very aware of Elderflower look-a-likes. Here’s a photo of Ash or Rowan in flower, growing above an Elder shrub which is not in flower. It would be an easy mistake to harvest the flowers believing them to be Elderflower, when here is nothing to compare them with.

Japanese knotweed, sweet sour yoghurt.

I so enjoyed harvesting, cooking and eating Japanese knotweed today, for the first time in my life.

I found several patches of the plant locally and harvested using a small knife, in much the same way as you would asparagus, except above the ground. The more mature stems were hollow, younger ones were very like asparagus within. Some had thin stems, some fat. I harvested young shoots, about 6 to 8 inches long, took them home, stripped away the leaves and thoroughly washed the stems before chopping them and boiling for 5 minutes in a little water.

The taste was very rhubarby; tart, sour and in need of some sweet. Once cooled a little, I mashed the soft stewed stems with a little banana, homemade yoghurt, a dab of honey and a good pinch each of ground ginger and cinnamon. When combined to my liking, I served in a small bowl and garnished with torn basil leaves.

The outside of the knotweed was more fibrous than I had expected so next time, I shall either push the stewed stems through a fine sieve or pulverize them with a blender, before mixing with the other ingredients. Stringiness aside, this is a delicious dessert! Maida Silverwood’s book proposes freezing stewed knotweed and I shall certainly have a go at that, when I find more of it. I will also keep an eye on how the cut stems repair at my harvesting spot.

Please be aware of the rules for rhizome disposal for this plant in your locality. In some countries it is a criminal offense to allow spread of the plant by careless disposal of the roots.

The roots were apparently used in ancient Chinese medicine for menstrual and post partum problems. It is certainly very astringent to taste and thus must have a drying, constricting effect on the body, at least to some extent.

I’ll do some research into the similarities with rhubarb and more historic medicinal uses. It is truly delicious and if you are a rhubarb fan I am quite certain you could also come to love Japanese knotweed.

Japanese knotweed

Japanese knotweed (polygonum cuspidatum) is an extremely invasive non-indigenous plant and gardeners who know it are generally distressed to find it on their patch. However, today I spotted this deliberately positioned specimen, growing happily in the Hortus Botanicus, Amsterdam. It’s even got an identification plate!

I once saw Japanese knotweed growing into a house which was being auctioned, yes into it, through the walls and under the floor! Needless to say, I didn’t make an offer to buy the place.

Seeing the plant reminded me that it is edible and apparently rather tasty too. According to the late Maida Silverman in her book, A City Herbal, it can be harvested and eaten in the same way as bamboo shoots, at this time of year. New York forager Steve Brill seems to like it, likening it’s taste to rhubarb. He also mentions it’s suitability as a companion plant, due to pesticide qualities. Personally, I don’t find the plant calls me to try it and I worry that by harvesting young shoots, the plant would further proliferate, in an attempt to survive. I hope I’m wrong because there is plenty of this plant growing in Amsterdam and I do love rhubarb crumble! What a great foraging plant this could be.

I’d love to hear from anyone who has tasted this plant. It is said to be quite tender, when cooked and to act as a gentle laxative. I’m also keen to know if harvesting, without pulling up the roots, would increase the plant’s chances of survival.

I wrote to Steve Brill about the harvesting issue. Here’s his reply…

On Apr 18, 2012 1:16 AM, “Steve Brill” wrote:
>
> Hi Lynn,
>
> Thanks for writing. As far as I can tell, it spreads wherever it can whether or not it’s harvested.
>
> Happy Foraging!
>

So knotweed crumble, here I come!