Welcome to the Scottish Invasives blog. Invasive non-native species (or INNS) are plants and animals that have been introduced to areas outside their natural range. INNS are currently recognised as one of the greatest threats to biodiversity. The Scottish Invasives blog is intended as an informal forum for those interested in invasive species control. If you wish to contribute, please get in contact. You can click on any of the images to see them at higher resolution.

Thursday, 14 October 2010

Himalayan knotweed as bad as Japanese knotweed?

I have recently discovered quite substantial stands of Himalayan knotweed near to the river Blackwater, along the way I discovered a house which is obviously inhabited by a builder of some sort and had recently done some building work of their own...I wonder do they realise what this plant is poking up from their building soil?!?! I found out that the house a mere 200 m downstream was the son to this household and guess what was in his back yard too! Classic example of spreading through top soil. Can anyone tell me if Himalayan knotweed presents the same danger to building work as Japanese knotweed???


  1. There are a number of other knotweeds out there. This one is a separate species to Fallopia Japonica and therefore is not included in the legislation that criminalises it's spread. Little is known about it in this country apart from that it spreads vigorously and through rhizomes and seed. There doesn't seem to be a figure for the size of rhizome as with Jk or it's ability to break through concrete type surfaces. I've never had experience of this plant but would suspect it has the same properties.

  2. Bekka Corre-Close14 October 2011 at 01:28

    Funny timing...I have just had a report of a plant that looks very mcuh like Himalayan knotweed but I still need to confirm it. Is there any info available on it? NNSS hasnt got an ID sheet for it.

  3. Bekka Corrie-Close14 October 2011 at 07:52

    Haha- just read the date of this post. It is definatly Friday... oops! Anyhow - what have you done with it?