I have a plant that just grew this year, I need help identifying what it is. Someone said a thistle, it doesn't have pickers on the stems. Another suggestion was a blue chrysanthemum

to NGA

I had one of those in California. Its a type of Aster but the name has fallen out of my head. They go dormant in the winter - at that time you should cut them down to the ground so the new stems can come up.

Where are you located? Did you live there last year? That plant is pretty large to have just showed up. I suspect it came up this spring from the root. They can get pretty large.

I live in western new york. Lived here over 20 years and this is the first year it came up. It is getting very huge. Should I cut it down once it gets closer outside

Why cut it down? I'd leave the stems for winter interest, they provide habitats for overwintering insects. You can cut it back in Spring. Fantastic autumn plant.