I am not sure what type of grass that is but assume it is a weed that has invaded your garden. Once weeds have made their way amidst your other plant they are hard to control with herbicides so hand digging or smothering them with newspaper or cardboard and a mulch at least 3 inches deep are the most practical ways to fight off such an aggressive sounding weed.  If this weed is local to your area than taking a sample to the nearest Master Gardener clinic would be the best place to get proper ID of this weed and learn  how to control it in your climate. Keep growing - but not Torpedo Grass - Marianne Binetti