Hi,

I've spent the last week digging and sifting the rhizome system of an infestation of Japanese knotweed.

however I've now come up against the fact that it is running underneath the driveway/patio.

I thought i had caught it before it would have spread there (and indeed it is relatively clear) however there was one 'crown' perhaps a meter at the closest point to the patio and as a result there two main roots heading off directly underneath the driveway and patio.

I'll take the bricks and patio slabs up if nothing else presents itself but if anyone has any help/tips for removing/killing a root system underneath non-diggable area it would be *greatly* appreciated.

T