How far do Japanese Knotweed rhizomes and roots go down

How far do Japanese Knotweed rhizomes and roots go down.

On large well established Japanese Knotweed infestations the roots that are also called rhizomes have been found to go down as far as 3 meters in to the ground and out 7 meters from the crown of a signalr plant.

More Japanese Knotweed FAQ’s.