I'm assuming this is nutsedge (see pics).

Hello Paul,

The reason why sedge herbicide hasn’t been working is that this is not sedge. I believe you have quackgrass. Quackgrass is aggressive and spreads readily by underground rhizomes that can travel great distances. The smallest portion of rhizome can start a new clump of grass.

Please see the articles below and confirm that your intruder has the characteristics of quackgrass and not nutsedge. Nutsedge can be identified by the reddish crown, triangular cross-sectional stem and mid-veined leaf. https://www.canr.msu.edu/resources/yellow-nutsedge-cyperus-esculentus

Quackgrass has a fibrous blade, can be identified by the clasping auricle and white thick rhizomes. https://turf.purdue.edu/quackgrass/

Quackgrass is indeed a difficult foe. There is no selective herbicide that will kill crabgrass and not damage cool season grasses. Glyphosate and fluazifop are effective in decreasing the vigor of quackgrass, but care must be taken to limit the contact with desirable turf, as it will be killed as well. Several applications may be necessary until the underground network of rhizomes is eradicated. Control is also addressed in the Purdue article.

Remember to always read and follow label instructions for your protection and for the environment. The label is the law.

Hope this helps.

Hello Paul,

Your pictures did not attach to the thread.  Is it possible they were larger than 8Mb?  To attach pictures:

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Click the “Drop files here or choose them” below the response box to attach them.

You can upload .jpg, .png, .gif, .txt, or .pdf.

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Hello Paul,

I see the other photos now. No nutsedge. I see quackgrass and possibly some tall fescue, but no nutsedge. Whether it is quackgrass or tall fescue, your options for control are the same. Apply a nonselective grass herbicide that will kill the quackgrass, fescue and any desirable grass it comes in contact with. Then you will need to reseed or sod.

If you want a positive identification, you can submit a sample to the MSU Diagnostic Laboratory. They will identify the specific type of grass. There is a cost for this service. The fee schedule, directions on how to take a sample and the form that must be submitted with the sample can be found at this website: https://www.canr.msu.edu/pestid/

You can also send these photos to <personal data hidden> and an expert on the faculty will give their opinion as to the type of grass and the control mechanisms.

Hope this helps.

Hello Paul,

Please take photos of the margin where you have brown and green grass in the same picture.  Make them close enough that we can see details on the blades.  We need to look for lesions on the blades - you may have a fungus outbreak.

When you do this, please start a new question thread so it can be tracked separately and not linked in with the nutsedge topic!

Thanks.