SHORT ANSWER: No, Japanese knotweed is not poisonous. In fact, the plant can make a tasty and nutritious addition to all sorts of different recipes!
Japanese knotweed is a troublesome plant that causes a lot of problems here in the UK. It grows very quickly, it can cause damage as it spreads, and if there's Japanese knotweed in your garden, you may find it difficult to sell your property.
Still, knotweed's not all bad. Unlike some other invasive plants (such as giant hogweed, whose sap can cause severe skin inflammation), Japanese knotweed is not directly harmful to humans - you can actually cook it and eat it with no ill effect.
Of course, before you start munching on the mysterious plant that's growing in your garden, you should first make sure it actually is Japanese knotweed and not some similar-looking species that could make you seriously ill.
Learn how to identify Japanese knotweed
How to prepare Japanese knotweed
Japanese knotweed can be incorporated into a wide variety of recipes. This Guardian article has a number of enticing suggestions, including a rather yummy-sounding dessert called strawberry and knotweed fool; we also recommend this post from the Forager Chef blog, detailing an American chef's experience of cooking with knotweed.
Both of these articles observe that Japanese knotweed tastes similar to rhubarb, and as such, it can be added to many dishes that would normally include rhubarb. Why not serve knotweed as a side dish with pork, or try your hand at baking a Japanese knotweed crumble?
As we've previously discussed on this blog, you can even make drinks out of Japanese knotweed. It's a very versatile plant (but don't even think about planting it in your garden!).
So Japanese knotweed isn't poisonous to humans - what about animals?
Animals don't necessarily digest food in the same way humans do, so many foods that are suitable for us are very bad for animals. Chocolate is a well-known example; while delicious for humans, it's toxic for cats and dogs.
Is the same true of Japanese knotweed? Well, we don't know for sure what effect Japanese knotweed has on cats and dogs - you certainly shouldn't feed it to your pet, but if Fido or Felix should snack on some knotweed when you're not looking, it's unlikely to cause any harm. Be sure to contact your vet if you think your pet is having a bad reaction to something they've eaten.
What animals can eat Japanese knotweed?
Many grazing animals - including sheep, goats and horses - can safely eat Japanese knotweed. But before you rush off to buy a goat, bear in mind that only a qualified invasive weed specialist can completely eradicate Japanese knotweed from your property.
If you're concerned about Japanese knotweed growing on or near your land, call Taylor Total Weed Control on 029 2039 7554. As members of the Property Care Association (PCA), we are qualified to deliver Japanese knotweed treatment programmes that conform to the very highest standards.
Request a free Japanese knotweed survey