Knowledgebase
Yellow nutsedge #870775
Asked May 30, 2024, 1:40 PM EDT
I am having trouble killing yellow nutsedge in my lawn. Looking for advise on killing it. Also, is their a pre-emergant I can use that will prevent it before it emerges?
I have used ortho nutsedge killer wth very limited success and trimec lawn weed killer which states it also kills nutsedge. I have put down several applications.
Thank you for your time in this matter.
Greg
Monroe County Michigan
Expert Response
Hello Greg,
The grass in the photo is not yellow nutsedge. The photo does not show the details of the plant structure well enough to identify it positively, but it appears to be a grass species (possibly tall fescue). Please carefully isolate a grass plant and take detailed photos of the stem, blade and joint characteristics. Respond to this question, add the photos and we may be able to provide a more informed identification. The following website gives detailed instructions and examples of the type of photos necessary: https://www.canr.msu.edu/news/grass-photography-tips-for-id-help-us-help-you
In the meantime, applying the products you have been using will have no effect on this grass. You should not apply those products any longer.
Hello again Greg,
Your response did not come through. Please try again. If you were trying to attach more photos, here are some tips for attaching photos:
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If you do not want a positive identification first, you may kill the grass by applying a non-selective herbicide (such as glyphosate) to the undesired grass. Be careful in applying the herbicide, because it will kill all grass species it comes in contact with, not just the one that you do not desire. Once the grass dies off, you can spot seed the bare area with grass seed,
Hope this helps.
On Mon, Jun 10, 2024 at 9:12 AM, Greg Newsom<<personal data hidden>> wrote:
On Sat, Jun 8, 2024 at 9:50 PM, Ask Extension<<personal data hidden>> wrote:
----- Forwarded Message -----From: "Greg Newsom" <<personal data hidden>>Sent: Mon, Jun 10, 2024 at 9:14 AMSubject: Re: Yellow nutsedge (#0140695)
On Mon, Jun 10, 2024 at 9:12 AM, Greg Newsom<<personal data hidden>> wrote:
Hello again Greg,
Based on what I can see in the close up photo, this is tall fescue - it is rolled, prominent veins with no separate midvein, and no ligules that I can see. https://turf.purdue.edu/tall-fescue/
Yellow nutsedge is a completely different plant: https://extension.psu.edu/yellow-nutsedge-id-and-control-in-home-gardens
You may submit a sod sample to the MSU Diagnostics Lab if you would like a second opinion. Carefully capture a sample of the grass and send it to the MSU Diagnostic Labs for positive identification. The following website describes the services and the fee structure for analysis performed by the Diagnostic Lab.: https://www.canr.msu.edu/pestid/
This website provides directions and tips for taking a good sample:
https://www.canr.msu.edu/pestid/submit-samples/
No matter what the identification of the grass is, that grass cannot be selectively killed off. You would need to apply a non-selective herbicide to it that will kill any desirable grasses around it. Once that undesirable grass is killed off, you can reseed those patches in the lawn.
