Knotweed. This stuff is chic in foraging communities, but I didn’t find out about it through a wild food book or online group. I read about it in one of my favorite cookbooks: Provence Harvest by Jacques Chibois. Chibois’s restaurant, La Bastide St. Antoine has a garden where Chibois is said to have hundreds of old and obscure herbs and plants. Don’t even think about planting it as an addition to your garden though, no matter what someone tells you. You can eat knotweed, sure, but it’s also the most invasive plant I’ve ever seen. Period. See my note on caution near the end of the post for more on how to safely handle and dispose of the plant.
If you don’t know where any knotweed grows, look in disturbed areas, and places that have been forgotten or aren’t tended much, like former gardens or abandoned lots. Just look for the tall, bamboo looking thicket below. I’ve spotted it in plenty of other places since, from parking lots, to gas stations and roadsides, near railroads, and plenty of other places–many of which get sprayed by the city.
This Spring I was ready for it, and I’ve cooked about 100 lbs so far, more than enough to put together some thoughts and recommendations about how it would like to be cooked. Here’s some opinions on harvesting, cleaning and cooking.
Knotweed, grows quickly, and you want to get it young, since it gets very stringy and fibrous as the shoots grow taller. If you come across some and they’re already tall and leafy, make sure to look around and inside the network of shoots, there might be younger shoots that are just emerging and tender. Shoots about 1 ft tall or smaller are the best, since, the bigger they are, the tougher the skin.
Cooking is easy, albeit it weird. I cut the plant from the base, remove the leaves, and wash it in cold water. Then it’s ready to go.
It’s related to rhubarb, so the first thing you’ll notice is a sour note from the high amount of oxalic acid. It tastes vaguely like rhubarb, but with a more earthy quality. Where rhubarb pairs naturally with red, ripe fruits, knotweed is much more at home with fall fruits like apples, pears, and grapes. It’s bit hard to describe.
There’s more to knotweed than flavor pairings though. You should know that if it gets wet, it turns slimy, quick. Cooking mellows this, but the texture of the hollow stems is, not pleasant. They disintegrate during cooking like rhubarb, but with a stringy texture that can be unpleasant, especially if the stems are older, and taller than a couple feet. Peeling the stems works to remove stringy fibers, but if the stems aren’t short, young and thick, you won’t get much yield.
The first thing I do with knotweed is cook and puree it in a blender, then freeze for later use. Like the paw-paw, which also has a funky texture after removing the seeds, making knotweed into a puree opens the door to possibilities, as well as bypassing the slimy, flaccid texture of the cooked shoot. Afterwords, to make a something with the knotweed I just pull some of the puree out of the freezer and fold it into things.
So what the heck can you do with it?
I don’t recommend knotweed as a vegetable really, unless it’s very, very young and firm, and even then, I would mix the shoots with other vegetables since their sour flavor is strong. I don’t see myself cooking knotweed in savory preparations for customers, barring the discovery of some awesome recipe, which is possible, but I feel, unlikely.
However, when cooked with fruit, or sweetened, I don’t mind it. As I mentioned, it pairs great with pears and apples. Other friends of knotweed are refreshing herbs like cilantro, lemon balm, spearmint or peppermint. It’s also good with cream and dairy, as well as warm spices, which round out it’s flavor. When this goes on the restaurant menu, I’m going to call it Asian rhubarb, since no one will ever pay 8 dollars for a dessert made from something called knotweed.
Anyone else cooked with this? I’d love to hear about it.
Proceed with Caution
Like I mentioned, knotweed is a horribly invasive plant–the worst I’ve ever seen.
- Just because you found a big patch, doesn’t mean you should eat it. Park service and state workers regularly spray knotweed colonies with herbicide in my area, especially along roads and railroads. If the plants look at all wilted or sickly, stay away.
- Don’t compost your knotweed. Knotweed is related to bamboo, and can regrow like a literal plant zombie if you toss it in your compost. Bake, boil, microwave, incinerate, or otherwise denature any scraps you have from cooking to avoid an infestation in a place you live.
Sweetened Japanese Knotweed Puree
- 3 lbs about 10 cups chopped young, japanese knotweed shoots, washed, leaves removed, peeled if taller than 1 ft
- 1.5 cups sugar or an equal volume of another sweetener, like maple syrup (remember liquid sweeteners will contain more water though, which will have to be reduced to get a similar consistency)
- 1/2 cup water
- Chop the knotweed shoots into 1 inch pieces. In a deep saucepot, combine the knotweed water and sugar. Cook, uncovered, for 15 minutes on medium heat, until the knotweed is completely soft, and has given off a lot of water.
- Transfer the mixture to a highspeed blender and puree until very smooth. Transfer the puree to a container, label, date, and refrigerate until needed. The puree can also be frozen.
After cooking, the sweetened knotweed puree can be used for all kinds of things: cake fillings, frosting, or something like the simple mousse below. See the knotweed mousse recipe here.