Welcome, Maysemaze! Yes that is nutsedge in bloom and it is a nasty, nasty weed. I have found that it is lighter in color than daylilies, so I can dig it out before it goes to seed now... usually! I did find one that was seeding and couldn't get my shovel fast enough, lol!
As others suggested, it is good to label the daylilies with the name and to make a map. I do hope that you will post photos of your daylilies next year. We would love to see them!
