Knotweed or Japanese knot weed is quite a difficult weed to control and requires some time to be able to control it effectively.One of the best way to kill it is by spraying it with RoundUp weed killer.
\nRoundUp contains Glyphosate which is a systemic herbicide that acts by blocking a plant\u2019s enzyme system.The herbicide is absorbed through growing leaves and stems where it is trans located throughout the plant and root network.It kills virtually all annual and perennial weeds including grasses. Glyphosate is quickly broken down in soil or sediment and is harmless to animal life.It might take several applications, but it will work.
\nThis is best carried out in the spring or when the plant is actively growing,just as the new shoots start to grow.Apply in dry weather that lasts for 12 hours.
\nA number of applications will be required over a 6 month period.
\nAnother method which is very effective if you have the time is to cover the area effected with knotweed with black plastic or old carpet,treating the shoots as they appear around the edges.This can take up to 12 months but for example if you are renovating a house and planning to move on the garden later it can be quite useful.<\/p>\n