Edible flowers are often used as a garnish or as an ingredient in salads. While not all flowers are edible, there are many out there that are. Very few supermarkets carry edible flowers, but they are available at specialty markets that carry gourmet produce. These flowers can be stored up to a week in the refrigerator as long as they are wrapped well. This is fine if they are to be used in a salad, but when they are used in cake decorating they need to be fresh.