Thursday, April 16, 2015

Japanese Knotweed for Eating and Playing

Japanese knotweed at the ideal size for recipes

We have conflicting feelings about one of the most abundant invasive plants in the Northeast, Japanese knotweed (Fallopia japonica, syn Polygonum cuspidatum). Yes, it is edible when it first comes up in the spring, and purportedly it has all kinds of medicinal properties, but is its potential edibility blinding some people to the fact it is also terribly invasive? I cringe all the time when I see people wish knotweed grew in their area! We have witnessed many native habitats taken over by a mono-stand of impenetrable knotweed forests, all to the detriment of diversity and a healthy ecosystem. Invasive plants like Japanese knotweed are successful because they seed prolifically, grow faster and earlier than native plants thereby cutting off sunlight for the smaller, slower-growing plants, and invasives tend to alter the soil making it undesirable for the native plant populations. While we would never advocate for the CT DEEP's suggestions of poisoning and spraying populations of invasive plants, we also feel we shouldn't gloss over the destructive nature of Japanese knotweed for romanticized versions of wild edible plants.

The history of the introduction of Japanese knotweed to North America  plus some identifying information can be found in the Wild Edible Notebook, a monthly e-publication put out by Wild Food Girl for a nominal subscription fee. We were very happy to contribute to the April 2015 edition.

Over the years, we have come up with several recipes to eat the spring shoots of knotweed, trying not to present them as an ideal solution to the invasive plant problem, but rather as an alternative to spraying or ignoring your local knotweed sources. Eat the Invasives! But also remember to curb their spread by harvesting responsibly and properly disposing of any plant material that may take the opportunity to root and spread further.

We have started collecting some of the dried, smaller hollow stems of knotweed to use as biodegradable straws. They are not completely impervious to getting wet over hours of being immersed, but are useful when sipping drinks around the house, and kids get a real kick out of wild-crafting with natural items they can find and manipulate on their own. Gillian has even crafted a blow-dart gun with the hollow tubes, using the larger lower stalks for the "gun" by cutting off the joints at both ends, and making the "dart" from smaller diameter stalks that are have the closed joints at both ends to provide air resistance when blown out of the "gun" tube. Involving your kids in the hunt for wild foods can be fun for them, even if they are just fooling around while you do all the dirty work of harvesting. Sword fights with dried knotweed stalks are always fun, and the hollow tubes can be cut down to use as small bowls and vessels while building fairy houses.

Lots of potential straws here, as well as building material for kids and their imaginations
Eat the knotweed, play with the knotweed, but don't spread the knotweed.


Livia said...

I encountered knotweed for the first time 4 years ago when a friend was kind enough to let me garden in her backyard. And now I have joined her in the perennial fight against them. Shockingly, we are making some progress fighting it back, even though it requires weekly weeding to not relinquish the what we've cleared.

Least year I tried eating it for the first time and found it way to boring to be worth the risk of moving the plant pieces into an area that wasn't already infested.

But this year I was researching Japanese coming before the Edo period and came across a vegetarian dashi recipe that calls for dried knotweed.

So I have some nice thick young shoots that I've brought home and cleaned. But now I'm pondering drying them. I have no data. So so you have a guess whether they'd be better peeled before I dry them or left unpeeled? And then I'm guessing split them in half and cut into think strips to air dry.

The 3 Foragers said...

I would guess peeling the knotweed depends on the age. Sometimes the strings can be horrible and almost like splinters. We dried some to powder, so the stringiness wasn't an issue.

Livia said...

Peeling them went well. I had picked stalks that were about ½-¾" in diameter and just used the bottom-most section where the walls were thickest. Then cut them into strips to dry. Since I was looking for something to flavor broth, how easy it would be to chew wasn't an issue.

But it still didn't have the peppery taste described in the research.

But I lucked out with my weeding and pulled out a huge chunk of root that was pretty solid, instead of all knobbly. So I cleaned, shaved, and dried that. This is clearly the right ingredient. It immediately smells like a particularly piquant radish.

So back to weeding the garden