When I was a young lad, the family took a road trip south to Arkansas to visit a (past) neighbor. Even though chickory is native here in Minnesota, I had never seen it before, and seeing the large blue swaths along the highways, I convince Dad to stop so we could see what they were. I collected seed and planted them back in Minnesota. One plant grew. Two or three years past, and I saw them starting to come up in nearby road side ditches. Even at 12 years old I was savvy enough to know about invasive plants, and this set off an alarm for me. I spent the next 8 years searching and pulling every specimen I could find. (And this is one time that I was actually successful!)
Now 45 years later, I've seen native chicory in dry Minnesota prairies, but always nicely coexisting with other native materials, and not in large swaths. I am still baffled why it hasn't "jumped the fence" as it did in my youth.