It's pretty much what I have to do in my strawberry bed and am repeating very soon. No idea why couch and strawberries seem so closely bonded but they are. First I dig up all the roots I can, let the patch sit for a few weeks and see how many seeds have sprouted, then get those and I'll spray whatever I can't seem to get out. When I feel things are in better shape, I add manure, and other stuff then put them back as I don't have any other place for them either. This year they'll be heavily mulched with straw which seems to keep the weeds at bay longer.