For those of you new to Japanese knotweed (Polygonum cuspidatum), it grows fast.
REALLY fast. It goes from fat shoots popping up from the ground to chest high in a matter of weeks.
And if you don’t get to visit regularly – you know, because you are under stay at home orders and the patch is all the way across town – it’s very easy to miss the optimal period.
Knotweed shoots are best when shorter than 12 or so inches. If they are taller than that, and haven’t yet started branching, you can try breaking the stalks (like you would for asparagus) to harvest the tops which are still tender. Older roots produce thicker shoots; thin, spindly shoots indicate the growth edge of a knotweed patch. These thinner shoots are more tender, but you have to collect more of them.
The best thing about knotweed is how well its flavor melds with other food. One excellent option to combine the sour but earthy flavors of knotweed with the other star of spring: rhubarb. This week’s recipe pairs these two foods – which are distantly related in the Polygonaceae family – in a versatile compote. Or maybe it’s preserves. Or jam. I know it’s not jelly, but I’m still pretty fuzzy on the distinction between the rest! Maybe we’ll just call it a “sauce”.
The Knotweed Rhubarb Sauce has a pleasantly sour flavor that works well in both savory and sweet dishes. It can even be used as a simple spread on biscuits. The sauce would also dress up baked pork chops. I used it for a crumb bar recipe I normally prepare to use leftover cranberry sauce during the holidays, and it turned out fantastic. The sophisticated flavor complements a morning cup of coffee for a light breakfast, and it’s healthy too – full of nutrients and refined-sugar-free. Even my very picky teens enjoyed these crumb bars.
Remember when preparing knotweed to discard any bits of stem and leaf EXTREMELY carefully. Pieces of stem can grow entire new plants, creating new infestations. You can cook the bits to kill them, or put them in a sealed container before throwing them away. Do not just toss them into your compost bin without some pre-treatment to kill the plant material. Depending on the age / size of your knotweed shoots, you may want to peel them, although I generally skip this step.
Knotweed Rhubarb Sauce
Makes approximately 3.5 cups
- 1 lb rhubarb, chopped into 1/2″ pieces
- 1/2 lb knotweed, chopped into 1/2″ pieces
- 1/3 cup applesauce
- 2/3 cup honey (or more, or less, to taste)
Toss everything into a large sauce pan over medium heat. As the mixture comes to a simmer, turn the heat to low. Stir frequently to prevent burning. The knotweed will melt – yes, in fact – infusing the sauce with its robust tart flavor. Continue to simmer until the sauce is very thick, 30 or so minutes. Or longer, if you have that kind of attention span. You can add more honey if desired for a sweeter sauce (or only use 1/3 cup honey to start, for a more sour result). Remove from heat and allow to cool completely before using in the following crumb bar recipe. Refrigerate remaining sauce up to four weeks.
- 2 cups almond flour
- 2 Tbs coconut flour
- 1/4 tsp salt
- 1/3 cup honey
- 1/3 cup melted unsalted butter (use coconut oil for strict paleo or vegan option)
- 1 1/2 cups Knotweed Rhubarb Sauce
- 1/3 cup reserved crust mixture
- 1/4 cup chopped pecans
Preheat oven to 350. Grease a 9″ square pan with butter or coconut oil, or line with parchment paper.
Mix crust ingredients in a medium bowl. Reserve 1/3 cup crust mixture for the topping. Press the remaining mixture into the bottom of the pan. Bake 10-12 minutes, until it starts turning golden in color.
Remove crust from oven and allow to cool 5 minutes. Mix reserved crust mixture and chopped pecans. Spread the knotweed rhubarb preserves on the cooled crust, and sprinkle the topping evenly over the preserves. Bake an additional 20 minutes. Allow to cool before cutting into 16 pieces. Enjoy!
Note: this crumb bar recipe works equally well for leftover cranberry sauce during the holidays, or raspberry preserves, or with any other fruit sauce!
What wild food are you enjoying this spring?