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Strawberry and Knotweed Upside Down Cake

sliced cake with strawberrries knotweed and fresh cream
upside down cake

Japanese Knotweed, also known as Sally Rhubarb, is a unique ingredient in this Upside Down Cake Recipe. Fresh Strawberries and Black Pepper add sweetness and a slight kick to this quick, easy bake. The juice from the Japanese Knotweed and Strawberries cook down below the rising cake infusing the batter with flavors as the Strawberry Knotweed Upside Down Cake bakes. If you have stumbled upon knotweed and want to try it out, this recipe is a simple way to add this unique, foraged ingredient to a spring time dessert.

Japanese Knotweed Growing Next to a Stream
pieces of japanese knotweed
Harvested Japanese Knotweed, make sure to discard the leaves at the top

Japanese Knotweed resembles Rhubarb in texture and flavor, although Knotweed have a distinct earthiness to it. This recipe adds the bright, punchy flavors of strawberry with an additonal kick of black pepper to this foraged fruit cake. Using tradional ingredients is a great way to incorporate wild Japanese Knotweed into your cooking repetoire and seasonal rotation!


japanese knotweed fruit roll ups
Knotweed works as an ingredient in many different recipes, check out this fruit roll up recipe!
sliced Japanese knotweed with whole red strawberries on cutting board

Make sure to harvest knotweed when the shoots first emerge in early spring. The plant can grow to be fibourous, think a celery like texture, if you harvest later in the season when the stalks are taller. Young sprouts, sliced into small rounds will bake uniformaly and quickly when mixed with the juice of strawberries.

After harvesting your early spring season knotweed shoots, make sure to use only the bottom portion that does not contain the leaves for any recipes and rinse the stalks well! The instructions below use self rising flour which is a great ingredient to have on hand for any quick bake ups as it omits you having to add the leavening products by hand and cuts down on time spent mixing so that you can get back to exploring new and unique ingredients like knotweed.

sliced knotweed and strawberry cake
I prefer to serve this cake with a simple whipped cream lightly sweetened with Honey
sliced cake with strawberrries knotweed and fresh cream

Japanese Knotweed and Strawberry Upside Down Cake

A delightful mix of Foraged Japanese Knotweed and fresh Strawberries make this dessert a unique way to try out Knotweed in a simple recipe.
Prep Time 20 minutes
Cook Time 50 minutes
Cooling Time 15 minutes
Total Time 1 hour 25 minutes
Course Dessert
Cuisine Baked, Cakes, Sweets
Servings 8 people


  • 1 9 x 9 baking dish
  • 1 Hand Mixer


Fruit Mix

  • 1 Cup Japanese Knotweed
  • 3/4 Cup Fresh Strawberries
  • 2 tbsp Dark Brown Sugar
  • 1/2 tsp Vanilla Extract

Cake Batter

  • 1 Cup Sugar
  • 1 Cup Butter Softened at room temperature
  • 2 Cups Self Rising Flour
  • 2 whole Eggs
  • 1/2 Cup Milk
  • 1 tsp Vanilla Extract


  • Preheat Oven to 350 degrees, position rack in center of oven.

Fruit Mix

  • Slice Knotweed stalks into uniform rounds, about 1/3 inches in length. Discard tops containing leaves, (do not throw into compost as knotweed is highly invasive and easily takes root). I used about 7-9 small stalks to make a full cup of sliced stalk rounds.
    sliced knotweed fruit
  • Slice strawberries into uniform pieces. I prefer quartering the strawberries for this recipe as the batter bakes it pulls the juices from the berry, infusing cake with flavor
  • In a medium bowl combine sliced knotweed, strawberries, vanilla extract, and brown sugar. Stir until the sugar is mostly dissolved and all ingredients are incorporated.
    sliced knotweed and strawberries
  • Spread evenly over bottom of 9 inch by 9 inch baking pan
    sliced knotweed and strawberries in pan

Cake Batter

  • Place softened butter and sugar into large bowl, whip until mixture becomes a light lemon color, 3 minutes.
  • Add Milk and mix well
  • Add 2 eggs, and beat slowly until fully incorporated into mixture.
  • Slowly pour flour mixing as you go into butter mixture until all ingredients are mixed together, scraping sides of bowl as needed.
  • Add vanilla extract and mix on low into the batter is uniform in color and smooth.
    cake batter in bowl
  • Pour batter over fruit in pan, making sure to cover evenly.
  • Put baking dish in oven and bake at 350 degrees for 50 minutes.
  • Remove from oven and allow cake to cool and rest, soaking up the fruit juices for 15 minutes before serving with freshly whipped cream, lightly sweetened with honey.
    upside down cake with knotweed and strawberries


japanese knotweed fruit roll upThis is another unique way to incorporate Japanese Knotweed into your diet, check out my Knotweed Fruit Roll Up Recipe!
Keyword Japanese Knotweed Dessert, knotweed recipe, strawberry knotweed dessert, upside down cake
Tried this recipe?Let us know how it was!

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1 Comment

  • Reply
    Foraged Japanese Knotweed Fruit Roll Ups - The Sifted Field
    August 14, 2022 at 7:58 pm

    […] Check Out my Knotweed Upside Down Cake […]

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