They are so hard to tell the difference, right? Especially since Mugwort is called the Chrysanthemum weed! The one way to tell for sure which I can’t see too well in the photos is mugwort has tiny white hairs under the leaves and mums do not!  The tall height also indicates mugwort. This weed is agressive and spreads by underground rhizomes. It is important to get all of the root out. It might be easier to remove after a rain and use a garden claw to loosen the rhizomes and remove so you don’t break them into pieces.  I have some of this that returns every year in the same place, an indication to me that I didn’t get it all out, but at least I keep it under control. 

Good luck!

Dear Ms. Walfred,

Thank you for the quick reply. I’m not seeing any hairs on the undersides of the leaves. They appear to be smooth—I’ve included some more photos. The plants are currently standing around 2 1/2 to 3 feet tall. Thanks again. 

Then you have mums! My app confirms it also. Did you plant them there previously? Now is a good time to pinch them back so they produce more blooms. Here is a care sheet from our colleagues over at NC Extension: https://stokes.ces.ncsu.edu/2021/10/chrysanthemums-mum-care/

And this from Penn State: https://extension.psu.edu/chrysanthemum-care

Most people who grow them for fall color pinch them back now to promote more buds and to delay blooming time. 

So glad it was not mugwort! 

~Michele

Dear Ms. Walfred,