United Kingdom 
Do cornflowers come up every year
4 Jul, 2010
Answers
There is a perennial cornflower - Centaurea montana, which is very vigorous, to put it politely.
4 Jul, 2010
Previous question
« want to know what is best for the border that has a privet hedge
No they are annuals but if you let them self seed they will be back next year - so long as you don't weed them out!
4 Jul, 2010