I totally agree with Caroline, tried digging out quack grass for many years and it would spread because it is impossible to remove all the runners plus any tiny pieces that break off will grow. Finally I got tired of the hopeless task and got information on using fusillade II spray, it works the only thing that works against quack grass in my garden. Covering it here did not work as it sent its runners under the cover and would pop up wherever it wanted to grow.
