Squash are easier to destroy, than is generally assumed.
Couch grass has a perennial rootstock (Rhizome). Nevertheless, eradication is easy in the course of the summer if you continuously loosen your vegetable beds and hack off every stalk of couch grass just below the surface of the earth, won't have long to complain about couch grass. The reserves of the rhizomes are so exhausted by the constant destruction of the above-ground green parts, that they too will soon perish.