Wild Edibles: How to Eat Japanese Knotweed
Disclaimer: Eating certain wild plants can be deadly!!
Be certain to consult a professional (or a really good field guide) in order to positively identify this plant before trying this for yourself. The owners of this site will not be held responsible for any lapses in judgment or stupidity when handling or consuming wild plants.
A native to southeast Asia, it was introduced to the United States in the late 1800s as an ornamental and has since become one of the most invasive plants in the United States, quickly spreading across to more than 40 of the 50 states. It’s root system is so invasive and strong that it can damage foundations, buildings, flood defenses, roads and so on.
Despite its bad rap, Japanese Knotweed is a great source of food and medicine and one of my favorite wild edibles in the early Spring. And since it is an invasive species, you don’t feel bad about over-harvesting it. In this post I’ll explain how to identify and harvest Japanese Knotweed and how to make a simple but delicious recipe from your foraging.
How to Identify Japanese Knotweed
The problem with Japanese Knotweed is that once you typically notice it, it is usually too late to harvest for food. In early spring, it starts out as a humble shoot that quickly grows (over an inch a day!) into a mature plant reaching upwards of 10 feet high.
Although the time to eat it is in the early spring before it begins to turn woody (under 12 inches), you’ll want to be able to identify it during its later stages of growth as well so that the next year you can return in the early spring and harvest it.
Spring is the time you should be on the lookout for this plant. Here’s what to look for:
|In the early spring red/purple mottled green shoots appear from the ground and grow rapidly forming canes. This is the ideal time to harvest the Japanese Knotweed shoots. You’re looking for 6 inches or less.|
|Late spring shoots with initial branching. You can still harvest the plant at this point as long as it is under a foot. At this stage you’ll need to peel them before consuming, since the outside has begun to get more fibrous.|
By summer this plant has grown to its full size. Since it typically grows from a networked root system, all of the individual mature plants form what appears to be a large shrub:
|Here’s a good example of how the knotweed comes to form what looks like a large shrub.|
|Shield shaped leaves that are aligned in an alternate pattern.|
|In the late summer you’ll also begin to see the flower growth.|
During late fall and winter the knotweed’s energy will begin to travel back into the root system in preparation for the winter time. During this time the leaves fall and the stems die and turn brown. The stems (canes) typically stand during the winter which can serve as a good indication of next year’s growth.
|Since it grows in colonies, the winter skeletons are easy to identify from afar.|
How to Eat Japanese Knotweed
While you can eat Japanese Knotweed raw (it is tart and crispy and tastes very similar to rhubarb), ideally you’ll want to cook it. Since it tastes very similar to rhubarb, you can use Japanese Knotweed in any dish that calls for rhubarb – my favorite being strawberry knotweed pie…yumm.
Here’s a simple dish that I got from Steve Brill that I love:
Japanese Knotweed Surprise
Ingredients (for one serving)
- 2 cups sliced apples
- 1 cup sliced Japanese Knotweed shoots
- 1/2 cup apple juice
- sugar to taste (optional)
|Step 1: Gather your harvested knotweed and remove any leaves and stems.|
|Step 2: Chop the knotweed into a small enough size to fit into your cooking pot and peel those shoots which have begun to form leaves (these will have already begun to turn stringy).|
|Step 3: Throw the knotweed and chopped apples into a pot and pour apple juice on top, bring to a boil and begin to simmer.|
|Step 4: Simmer for about 20 minutes or until soft. You will notice that the knotweed seems to melt into a thick, sauce-like consistency.|
|Step 5: Once the knotweed turns to a sauce-like consistency, serve and eat!|
Japanese Knotweed Nutrition and Medicinal Information
Japanese Knotweed provides an excellent source of vitamin A and vitamin C. It also provides potassium, phosphorus, zinc, and manganese.
Japanese Knotweed is also an excellent source of resveratrol, the same substance in the skin of grapes and in red wine that reduces bad cholesterol and lowers the risk of heart attacks.
According to master herbalist, Stephen H. Buhner, Japanese Knotweed is very effective when it comes to treating and preventing Lyme’s disease. As an anti-inflammatory, it also helps the immune system to combat various infections, relieves symptoms of arthritis and can protect the body against neurotoxin damage.