First, positively identify the flower as edible. A lot of flowers are edible, but just as many are toxic. A good companion book for identification is Edible Flowers: From Garden to Palate by Cathy Wilkinson Barash (out of print, but still available in some stores). If youre not an experienced gardener, talk with someone who is or your local greenhouse about what kind of flowers you want to grow. Many supermarkets today also carry edible flowers along with fresh herbs. Check the quality of the flowers before you make a purchase. Flowers are highly perishable and usually expensive in markets compared to growing them yourself.