How to Propagate couch grass?
Propagates predominantly by spreading rhizomes (underground roots), although seed is also produced and can remain viable in the soil for some years

couch grass · Elymus repens
Also known as: felt; lagoon grass; quack grass; quitch grass; scutch; shelly grass; skally grass; squitch grass; twitch; twitch grass; witch grass
Growth begins early in spring, which can allow this plant to out-compete others that may need warmer temperatures; because of this and its ability to spread rapidly underground, it is often considered a weed. Roots are fairly shallow, so forking out may be possible in lighter soils, though any remaining fragments of rhizome may re-grow
Propagates predominantly by spreading rhizomes (underground roots), although seed is also produced and can remain viable in the soil for some years