Japanese Knotweed - What It Is & How To Control It

8th July 2021

Japanese Knotweed (Fallopia japonica) is an herbaceous perennial that spreads through rhizomes and is extremely invasive. It’s a large clump-forming plant, which grows up to 3M tall, with light green shield-shaped leaves.

Japanese Knotweed

It is native to eastern Asia and was introduced in the early 19th century as an ornamental garden plant. As early as the beginning of the 20th century it was widely recognised as an invasive species.

You must prevent the spread of Japanese Knotweed by law. Detailed information about this can be found by following this link: Prevent Japanese knotweed from spreading

Herbicide Control

For Domestic Situations = Do not attempt to control Japanese Knotweed yourself. Employ the services of a professional weed contractor who can deal with invasive weeds. For guidance of finding a professional contractor, contact Collier Turf Care.

For Professional Users = Gallup Hi-Aktiv Amenity, Roundup ProVantage, Synero or Icade, would need to be mixed with Prestige Super pH Buffer and Prestige Super Sticker. Stem injection alongside foliage spraying.

It is important to note that herbicide control may need to be repeated regularly for a number of years until the plant is finally eradicated.

There are no selective herbicides that can be used to control Japanese Knotweed in turf, you will have to repeatedly treat with a total herbicide to eliminate it and only once eradicated can you re-turf or seed.

By Chris Humphrey MBPR FQA, Technical Manager

For more advice and help, contact Collier Turf Care on 01328 700600