To start with, do not be afraid of knotweed. It is the gardener’s friend. If you have a knotweed patch, especially if it is a large and long-established patch, you can grow your vegetables right there, in the patch, alongside the knotweed. Knotweed is non-toxic, indeed, it is edible and has health-giving properties. It contains resveratrol (the good stuff in red wine). Is doesn’t sting, unlike nettles, and it has no thorns. Ideally, start in the centre of the patch and clear away dead stems in the winter. You can leave the edge of the patch for the time being. Allocate an area for a composter. You will only be using the compost you make from knotweed on-site as it is illegal to take it off the site (in the UK). Throw all the brown stems there then as the season progresses, throw the fresh green stems on that mat of brown stems so they rot down together. Knock the big lumpy roots out of the ground with a sledgehammer and add those to the centre of the compost pile so that they dry out and then die and rot down. Or you can drown them in a tub of water before adding them to the compost pile. Care must be taken not to carry any bits of knotweed off the patch that could contaminate other lands.