QuestionsHow to growFlowersSummer colour from seedblue cornflowers 0 Vote Up Vote Down Ann Fahey asked 15 years ago I love common garden blue cornflowers. I would like to know if the flower heads are edible or should they be just used for decoration in a salad for instance. 1 Answers 0 Vote Up Vote Down Gerry Daly Staff answered 7 years ago The blue flowers are edible and have been used also as a blue food dye.