Guack grass in our Lawn

Asked August 10, 2018, 3:41 PM EDT

Hi there............ We were looking over The U of M site for a solution but did find one. Not sure if there is one or we just didn't look good enough! We have quack grass slowing over coming our lawn and wondering how to stop this? Any ideas?

Minnesota quackgrass

1 Response

The first thing you should do is to be sure that you have quack grass and not crabgrass. The two are often mixed up. The treatment strategies for the two are very different. Take a look at the following three sites to be sure that you are dealing with quack grass.

https://www.whygoodnature.com/quackgrass-dont-call-me-crabgrass

http://growingtogether.areavoices.com/2017/04/21/is-it-crabgrass-or-quackgrass-in-your-lawn/

https://www.thespruce.com/quackgrass-crabgrass-easily-confused-lawn-weeds-2153114

I am going to answer your question assuming you have quack grass. If you decide that you have crabgrass, please disregard what I will say and get back to us.

For the immediate time, other than trying to pull it up, there is not too much to do. Even if you try pulling it up, you will leave behind root fragments that will generate more quack grass. However, there is something you can do now in 2018 to greatly eliminate how much quack grass you will see in 2019.

In late August to early September quack grass begins a very vigorous growth cycle. At that time try to kill the quack grass with a product containing glyphosate, such as Round Up. The quack grass should readily take up this herbicide, especially into its roots. Under ideal conditions, this may kill the quack grass before it releases any of its seeds. However, do this very selectively using a hand sprayer. Try to direct the herbicide directly onto the quack grass and avoid getting it onto surrounding grass. Within a few days, you should see the quack grass turning color and wilting. This will be your sign that the quack grass is dying. If some quack grass still looks unaffected, hit it again with Round Up. You may have to repeat this tactic next year as well. Getting rid of quack grass is not a single year project.

If you find that some grass has been killed in this process, you may need to do some reseeding next spring or, more preferably, this fall during late September. If you do re-seeding this fall, wait at least a week after you apply the Round Up before doing so,

But having said this, you still may have had some quack grass distribute seeds this fall. So here is where a pre-emergent herbicide comes in. In the spring of 2019, once the snow leaves your ground but before any greening up occurs, distribute some pre-emergent herbicide (Preen) on the ground. This should prevent any quack grass seed from germinating. But this will be tricky. The Preen treatment may retard the germination of any grass seed that you might have planted this fall.

Getting rid of quack grass is a labor intensive process and generally does not happen in one year. Have patience. This is one of the things that gardening teaches us.

Good Luck!!