Jeopardizing Nature: Japanese Knotweed

By: Amy Kikuchi

Social Media Coordinator, CYBN 
​Amy has a Master of Environmental Science from the University of Toronto and is passionate about harvesting healthy and delicious plants found around Ontario. Check out her website @ ecpickings for more content!

Japanese Knotweed (Fallopia japonica) is native to eastern Asia and was introduced to North America as an ornamental plant in the late 19th century. As many invasive plants do, Japanese Knotweed escaped gardens and is now one of the most aggressive invasive plants in Ontario. Japanese Knotweed prefers moist soils, but can be found in many disturbed areas.
 
The bamboo-like plant is extremely fast-growing and forms dense thickets that outcompete and displace native plants. Two-thirds of the plant is actually underground in an extensive root system, making it exceedingly difficult to remove.

But, did you know Japanese Knotweed is edible!?
 
Young Japanese Knotweed shoots look a little like asparagus, with a light pink-purple hue that turns green over time. ⁠ They have alternate leaves that are a rounded triangular shape. ⁠The stems are smooth and hollow, and make a satisfying “pop!” sound when snapped off. I prefer eating the early spring tender shoots, as the older plants become fibrous and stringy.

Sprouting Japanese Knotweed.

Pieces of Japanese Knotweed stem or rhizome can produce new⁠ plants, so be sure to dispose of the scraps properly! I usually microwave or bake the scraps in the oven on high heat before disposing them.
 
So what does Japanese Knotweed taste like? How should you cook it?
 
Japanese Knotweed has a flavour similar to rhubarb— sour, with a light earthy taste. Make sure to clean your harvest thoroughly, and be aware that the plant will be slightly slimy when it gets wet.

Young Japanese Knotweed shoots look a little like asparagus.

Chopped Japanese Knotweed.

If you’re not sure what to do with knotweed, my rule of thumb is that you can take any rhubarb recipe and substitute it with Japanese Knotweed. For example, they are a great substitution in recipes like Strawberry Rhubarb Crumble, Rhubarb Custard Pie, and Rhubarb Squares. I made some Japanese Knotweed Squares using this recipe as a base, and they turned out delicious!

Japanese Knotweed Squares.

Japanese Knotweed also makes a beautiful jelly that has a unique naturally pink colour.

Japanese Knotweed Jelly.

If you’re curious to taste Japanese Knotweed, keep an eye out for their sprouting shoots in the early spring.* They grow very quickly so the earlier, the better.​

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*If you are going to harvest Japanese Knotweed, make sure it has not been sprayed, as many regions use herbicides to try to control the invasive plant.

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Disclaimer: Do not consume any wild plant unless you are 100% sure of its identification. Be sure you are picking from non-polluted areas, away from roads, and where no pesticides or other contaminants may have been used. Consult your doctor before consuming wild plants.