Q: I have nutgrass in one area of my day lilies. What can I do to eliminate it?
A: Nutgrass is tough to eliminate in a flower bed.
Why not dig and divide the daylilies and wash the roots so you can remove any “nuts” you find?
You can plant them in another spot and then Roundup any nutgrass that appears in the first bed.
You could try spraying the bed with imazaquin (Image) but try the spray first on a small site. This chemical is labeled for use on several groundcovers but I don’t know if it is labeled for use on lilies.