Why the river valleys and the Manchester, Bolton and Bury canal corridor suit knotweed, and what to check along your own boundary.
Knotweed spreads from fragments of root, and rivers and canals are perfect for moving them. In Bolton the Croal runs down through Farnworth and Kearsley to meet the Irwell, and the old Manchester, Bolton and Bury canal follows the same valley. Where gardens back onto either one, a stand can arrive without anyone seeing it come.
Walk the bottom fence in spring for red-purple shoots, then again in July for tall hollow canes above the boundary. Pay attention to banks that flood, because floodwater can leave fragments behind.
Whoever owns the land it grows on. A survey of your own side shows whether it has crossed the line, and that record is what you hold if you need to raise it with someone.
