Many years ago I bought a solution that I could spray on and around my shrubs that killed couch grass. I have now have the same problem but am unable to find the 'solution' anywhere.
I can pull some of the grass out but it always breaks under the roots of the shrubs.
Any ideas folks?
Sadly they have stopped selling the product (used to be Weed-out I think). All you can do is very carefully spray the emerging stems with a translocatable weed killer. I add a little liquid soap to the solution as it makes it stick to the grass stems.
I have been cleaning out one of our borders that last few weeks. So far I have filled 12 compost bags with couch roots. And I can gaurantee that I have missed almost as much as I have removed.
I can't vouch for this, but I have read that a wild flower called yellow rattle 'eats' the roots of couch grass. This has been mentioned in various wildflower threads but I don't know if it would thrive under shrubs or not - or whether it would end up spreading like mad and being as much of a problem as the grass!