The japanese knotweed is just coming up now, it is edible, but how do you cook it?

Add a lot of sugar and cook it down like rhubarb.. Try this recipe

Japanese Knotweed Crumble

Prepare a knotweed compote (similar to stewed rhubarb) by cutting tender spring knotweed shoots, no longer than about 12"-18" (the thicker, the better; leaves removed) into inch chunks. Steam till soft -- about 10 minutes. Add sweetener to taste -- perhaps 1/4 c. sugar per 2-3 cups of steamed knotweed -- and a squeeze of lemon juice.

Prepare a crumble mixture:

Mix equal parts flour and oatmeal, say 1/2 c.each, with a bit of cinnamon, some sugar and a dash of salt.

Cut in butter, 1/3 stick at minimum and more if you like a richer crumble.

Butter a baking dish.

Put in the knotweed, cover with crumble mixture and bake in a medium hot oven, 350 degrees, for a half hour or so.

As you notice, measurements, times and temperatures are variable. This basic technique is flexible and adaptable – just like knotweed! Have fun, use up our invasives, and get something for nothing. One warning: the color of steamed knotweed has been called 'snot green.' A drop of red food coloring can assuage the squeamish who look at what's under that yummy, rich topping.