Japanese Knotweed

Martin Clear asked 13 years ago

I have an old yard and a neighbour pointed out a troublesome weed to me about a year ago. He called it Japanese Knotweed. I have tried to kill this with Roundup, by covering the area with stones after spraying with Roundup, by cutting all shoots away, and all to no avail.How can I kill this Japanese Knotweed plant. I think that it is now spreading and appearing around the yard?Tangman

1 Answers

Gerry Daly Staff answered 4 years ago
Japanese knotweed is susceptible to Roundup, but it has deep roots and the amount applied is usually now sufficient.

Cut the bamboo-like canes in autumn to about 30 above ground and insert a teaspoon of undiluted Roundup into each cut bamboo.  If there is a re-appearance in spring carry out the same procedure in May.