Pick flowers early in the day. Use them at their peak for the best flavor. Avoid unopened blossoms (except daylilies) and wilted or faded flowers. They may have a bitter or unappealing flavor. Do not use flowers that have been sprayed with pesticides, which often occurs along roadsides, or collect flowers from plants that have been fertilized with untreated manure. Generally avoid purchasing flowers from florists, garden centers or nurseries. These flowers are not grown for consumption.
Edible flowers have been used in the culinary arts for flavor and garnish for hundreds of years.
http://www.ext.colostate.edu/pubs/garden/07237.html
Tulips are also edible. The petals, if not treated with chemicals, make good garnishes. The bulbs can be poisonous, so avoid them.
Sue
