I found this article at the Aggie Horticulture page:
http://aggie-horticulture.tamu.edu/tamuhort.html

Please be sure to only work with flowers that are edible!!

Betsy

Candying or crystallizing flower blossoms

Candied flowers are nice to have on hand to add elan to plan baked goods and
other sweet treats. Top a cupcake or petit four with single violet or rose petal, or
wreathe your favorite cheesecake with all the blossoms of early spring. Good
candidates for candying are apple or plum blossoms, borage flowers, lilac
florets, rose petals, scented geraniums, and the violas­violets,
Johnny-jump-ups, and pansy petals.

This job takes a little patience; it seems to go more quickly if you do it with a
friend. The following recipe will coat quite a few flowers, but if you need more,
mix up a second batch.

Rose petals, lilac florets, and whole apple blossoms can wreathe a creamy cheese cake.

Candied Flower Blossoms

Items Needed:

Rinsed and dried flower blossoms, separated from the stem
1 extra-large egg white, at room temperature
Few drops of water
About 1 cup superfine sugar
A small paint brush
A baking rack covered with waxed paper

In a small bowl, combine the egg white with the water and beat lightly with a
fork or small whisk until the white just shows a few bubbles. Place the sugar in
a shallow dish.

Holding a flower or petal in one hand, dip a paint brush into the egg white with
the other and gently paint the flower. Cover the flower or petal completely but
not excessively. Holding the flower or petal over the sugar dish, gently sprinkle
sugar evenly all over on both sides. Place the flower or petal on the waxed
paper to dry. Continue with the rest of the flowers.

Let the flowers dry completely; they should be free of moisture. This could take
12 to 36 hours, depending on atmospheric humidity. To hasten drying, you
may place the candied flowers in an oven with a pilot light overnight, or in an
oven set at 150ƒ to 200ƒ F with the door ajar for a few hours.

Store the dried, candied flowers in airtight containers until ready to use. They
will keep for as long as a year.