This is Centaurea montana which is commonly known as Mountain Bluet or Perennial Bachelors Button. It is a very pretty blue color, one of the few plants that is blue.
It was purple.. a seedling variation. These are in an area west of the old Jack Pine, I wonder what color they will be this year? Centaurea montana self seeds itself all over. I have enough space in my wild gardens that I just let it go wherever it wants..however for you gals with more formal gardens you may find this plant invasive.
Centaurea montana grows 12 to 18 inches tall for me and it grows in full sun or part shade…I rarely water the “wilds” so it must not be fussy about water..and the deer don’t eat it, and Minnesota’s harsh winters don’t kill it:)