Land contaminated with couch grass cannot be digged with a spade, but must work it with the digging fork.
Couch grass reproduces through the underground rhizomes. From every limb, which is cut off with a spade when digging, an independent plant emerges. Therefore only use the digging fork! With her you can see the couch grass nests, that have formed in the ground, Lift out and shake off the soil that is stuck to it.