How to Kill Quack Grass
Quack grass is a perennial grass commonly considered to be a weed. Its main characteristic is its robust nature, making it difficult to remove from a lawn. It's Latin name, Agropyron repens, means literally "sudden field of fire," an allusion to its ability to rapidly consume an entire lawn. Quack grass is found in all states except for Hawaii, Arizona and Florida. Quack grass grows from rhizomes buried in the earth which produce thin, flat blades of grass which can reach 1 to 4 feet if left un-mowed. Control is difficult, but possible.
Apply nitrogen fertilizer to the quack grass to promote the growth of dormant buds in the grass. This will prevent grow back once herbicide is applied.
Spray the quack grass with an herbicide containing glyphosate using a spray wand and pump. Apply herbicide directly to the grass.
Repeat application of the herbicide every 30 to 45 days until the quack grass dies away.
Cover areas of dead quack grass with mulch to suffocate any remaining living grass and prevent new growth.
Kill Bad Grass
Spray actively growing grass with a grass killer, such as the non-selective herbicide glyphosate. Apply it only when the weather is not windy and when rain is not expected for the next two days. Reapply the grass killer to live patches if necessary. Pick up the resulting clumps of grass, shake off the soil and discard the clumps. An option is to rake away the grass. Cover the unwanted grass with six layers of cardboard, then cover the cardboard with 4 to 6 inches of mulch, such as leaf mold. If desired, punch holes in the cardboard and plant mature plants in soil beneath the holes, but watch for grass that may sneak through the holes. Pull that grass to remove it. Mow the grass with a lawnmower set at its lowest cutting height and during the hottest time of the year. For other areas of the landscape, use a weed trimmer to cut the grass short. Water the cut grass with 1 inch of water. During that time, the grass underneath the tarp will die from the excess heat created by the tarp and weather.
Apply the herbicide 48 hours after a hard rain to keep the herbicide from running off the plant.
Herbicide containing glyphosate is a non-selective herbicide, meaning it will kill any plant it comes in contact with. Spray directly onto the quack grass.
Spray when the wind is less than five miles per hour in any direction to prevent the herbicide from spreading.
- Cheyenne Botanic Gardens: There's a Quack Lurking in Your Lawn
- University of Minnesota: Controlling Quackgrass in Gardens
- University of California Integrated Pest Management Online: Complete Renovation -- Kill the Existing Turf and Weeds
- Los Angeles Times: Four Ways to Remove Your Lawn
- Fine Gardening: Four Ways to Remove Sod