Couch grass, also called quack grass, is a perennial grass that is considered a noxious weed in 41 states according to the University of Minnesota Extension. It produces new plants from the rhizomes that are found underground. One couch grass plant is capable of producing 300 feet of stems in one year, which is why it spreads so quickly. Couch grass is difficult to get rid of, but not impossible to kill if you're persistent.
Put on gloves to protect your hands and pull up the couch grass. Put the grass into a garbage bag for disposal.
Dig up the rhizomes that remain in the soil and place them in the garbage bag.
Spread mulch over the area where the couch grass was growing. Watch for any new grass growth and pull it up immediately.
Apply nitrogen fertiliser in the spring to the areas where couch grass is growing to break bud dormancy.
Spray the glyphosate herbidcide on the couch grass only. Reapply the herbicide every 30 to 45 days.
Apply the herbicide with a paint brush or sponge for couch grass growing in a flower bed or garden where fruits and vegetables are being grown.
Pull up couch grass or spray it with herbicide in the spring. Choose a day with no wind to apply the herbicide to prevent it from being blown onto nearby plants and grass. Check the weather forecast for rain in the next 48 hours before applying the herbicide. The rain will dilute or wash away the herbicide before it can work. Follow the directions on the bag of fertiliser and the bottle of herbicide for the amount to use. Wait until the fertiliser has had time to work before spraying the herbicide.
Don't use rye straw as mulch in the garden because quackgrass is often found in it. Use glyphosate only on the couch grass. It's a non-selective herbicide, which means it kills everything it comes into contact with.