Blue roses do not naturally grow because the rose doesn't contain the gene for the color blue. Florigene, a company in Australia, has succeeded in modifying the DNA code of roses by inserting the gene for blue from a pansy. These roses are not yet available as of 2010. True blue roses are only obtainable by dying the flower or spraying.
Dying Roses Blue
Remove bruised petals from the roses. Remove the leaves as they will absorb the dye as well as the petals.
Mix blue food coloring into a glass of warm water. The more coloring you use the deeper the color blue.
Cut 1/2 inch at 45-degree angle from the bottom of the stem of the rose and immediately put it into the dye. Use sharp scissors so you don't crush any cells in the stem. The rose will draw the water up the stem, gradually turning the petals blue.
Re-cut the stem after 24 hours and replace in the dye bath. If the rose isn't blue enough, re-cut the stems and let the rose sit for another 24 hours.
Hydrate the flowers by placing them in a bucket of ice water for an hour.
Remove any bruised petals.
Spray the flower with a light coat of the blue floral spray, moving the spray so it mists the roses rather than coating them. Three or four light coats are better than one heavy coat.
Let the spray dry between coats. The spray has a slight odor which dissipates after 24 hours.
About this Author
Katie Rosehill holds an MBA from Arizona State University. She began her writing career soon after college and has written website content and e-books. Her articles have appeared on GardenGuides.com, eHow, and GolfLinks. Favorite topics include personal finance - that MBA does come in handy sometimes - weddings and gardening.