Quack grass is a weed that is difficult to eradicate once it becomes established in your lawn or garden. There are several different methods to prevent it from infesting your yard and to fight it once it appears in your garden.
Although established plants have deep roots with rhizomes that are difficult to eradicate, plants that are just beginning to grow from seeds can be eliminated if they are caught early in the growth cycle. If you see new quack grass plants growing in your lawn or along the edge of the garden, quickly take steps to pull the weeds out or use a spot herbicide to kill the plants. Rhizome roots do not develop for the first two to three months, so pulling them up quickly may entirely eliminate that particular plant and stop it from spreading.
Another method to prevent quack grass from becoming established is to contain established patches of quack grass. You can accomplish this by keeping the patch mowed short so that the seeds are prevented from growing and spreading. However, after each mowing, carefully and thoroughly clean the blades of the mower to stop unintentional seed spread.
Fighting Established Patches
Probably the most effective method of killing and eradicating quack grass is to use a pre-emergent herbicide. Pre-emergent herbicides are effective in attacking unwanted plants and weeds before they are fully grown. However, in order for this method to work with quack grass, it is necessary to encourage the rhizomes to begin to grow and develop by using a nitrogen rich fertilizer where the quack grass is located in the garden. Without the fertilizer, the rhizome roots will remain dormant and the herbicide will not be effective. Usually, it is necessary to apply a pre-emergent herbicide several times during the growing season, since quack grass is a perennial that will return each growing season.
Once you have begun to treat an affected area, it may take several growing seasons to completely get rid of the weed. During this time, you probably will not be able to plant other desired plants in the patch area, since the herbicide will kill anything else that is growing near the ground where it is applied.
Another non-toxic method you can use to fight established patches of quack grass is to maintain a turf cover over the weed. You can accomplish this by using opaque plastic, canvas or cardboard to cover the ground and prevent the weeds from growing.
You can also spread clear plastic over a patch of quack grass during extremely hot weather. This will trap very heat under the plastic and basically cook the weed to death. Once the weather cools, pull the plastic up and remove the dead foliage and plant materials. You may need to repeat the process several times through the summer as new rhizomes become activated and plants emerge from the ground.
Preventing quack grass from growing and becoming established in a lawn or garden can be a long term project for the dedicated homeowner and gardener. Ultimately, the key to getting rid of this persistent weed it to deplete it of energy, either by repeatedly destroying it or by eliminating its ability to germinate.