Japanese knotweed is one of the most infamous invasive species in the UK, known for its ability to rapidly spread and thrive in any condition and its difficulty to remove. Whilst you may be very familiar with Japanese knotweed, you may not have heard of a very similar plant, Giant knotweed.
Giant knotweed and Japanese knotweed have very similar names, and indeed are both members of the Fallopia family, a species of flowering plants native to Asia. However, some people use the names ‘Giant knotweed’ and ‘Japanese knotweed’ interchangeably, but it’s worth knowing that these are in fact two different plants.
(Giant knotweed is not to be confused with Giant hogweed, another invasive plant. Read our blog post about Giant hogweed for more info on this nasty customer.)
Giant Knotweed vs Japanese Knotweed: A Comparison
As mentioned above, Japanese knotweed (Fallopia Japonica) and Giant knotweed (Fallopia sachalinensis) are both members of the Fallopia family, and as such have a large number of similarities despite being two different plants.
Both plants are herbaceous perennials, and they have a number of physical similarities. They both have reddish roots, large dark green leaves, and small flowers. They both follow a similar life cycle typical of perennial plants, revolving around dying down in the winter and regrowing in the spring.
The main differences between the two, as the name might suggest, is that Giant knotweed is significantly larger than Japanese knotweed. Giant knotweed is capable of growing to impressive sizes, over 4 metres in height, and a single leaf can span up to 40cm across! Another difference that differentiates one from the other is that the flowers on Giant knotweed have a slightly green tint to them, whereas Japanese knotweed flowers are usually purely white.
* * *
If you have a mysterious new plant blooming on your property and you’re not sure if it’s Japanese knotweed or Giant knotweed, why not take a minute to submit a photo to us today? We’ll get back to you as soon as we can and let you know whether or not you have a knotweed infestation.
Submit a Photo
Alternatively, if you’d like a FREE survey and a no-obligation quote about the treatment of knotweed on your property, reach out and contact us today to book your free survey! You’ll receive a no-obligation quote that will outline the course of treatment we will take, as well as a no-nonsense quote as to how much you can expect to pay.
Free Survey
Read More: Invasive Weeds You Might Find in Your Garden
Is It Japanese Knotweed?