We’ve gotten used to purple carrots, orange or purple cauliflower, and blue poinsettias, but who would have expected a rainbow rose? At first glance, these roses look fake. Although they are living roses, they are not hybrid crosses between different colored flowers, the way most new shades of flowers are created. The petals of rainbow roses have been injected with dye, and the rainbow effect is only one outcome possible with this process.
The Origins of Rainbow Roses
These brightly colored blossoms are the result of some very clever work by a Dutch grower named Peter Van de Werken. Looking to expand the market demand for cut flowers, Van de Werken and his colleagues began experimenting with developing new colors of roses, chrysanthemums, carnations, and a few other flowers. They began with white flowers and initially tried simply spraying the dye on the petals, the way they do with blue poinsettias, but the results were less than satisfactory. Then Van de Werken came up with the idea of having the flowers take up dye through their vascular systems.
Getting dye to absorb its way up the flower stem and out to the petals is not an easy task. For starters, most dyes contain molecules that are too large to work their way out to the delicate petals. Introducing a foreign substance into a plant also has the potential of harming it. However, after much trial and error, special dyes made from plant extracts succeeded in changing the petal colors vividly enough to make it worthwhile.
Initially, the roses were dyed a single unusual color by immersing the stem in a container of dye. Creating the rainbow effect requires an even more complicated process, which Van de Werken’s company guards closely. However, you can create a version at home.
Can You Grow Rainbow Roses?
Perhaps you’ve seen rainbow rose seeds for sale that promise to grow into brightly multicolored roses. Unfortunately, rainbow roses need to be created, not grown. As mentioned, rainbow roses are not the result of crossing two different colored roses, and even if they were, hybrid plants do not grow true to seed until they have been stabilized.
Instead of relying on these seeds, color roses yourself for much better results. You may not get the vivid colors Van de Werken produced because his team isn't releasing the details of the dye or the procedure, but since the method here is basically osmosis, you will be able to make a reasonable facsimile.
Equipment / Tools
- Sharp blade or knife
- Narrow glass containers, bud vases, or test tubes
- Plastic bags (optional)
- Rubber bands (optional)
- White roses
- Food coloring dyes
Choose Your Roses
Start with as many white roses as you'd like to use. Choose roses as the buds are just starting to open. If the buds are too tight, they may never open, and if the flowers have already unfurled, they will not have sufficient time to absorb the dye before they start to fade.
Shorten the Stems
Make a fresh cut in each stem. If you have long stem roses, shorten the stems to about eight to 12 inches, so the dye does not have to travel so far.
Divide Each Stem Vertically
Using a sharp blade or knife, divide each stem into vertical sections, one section for each color. Cut about three inches up each stem. Don’t make more than three to four sections in each stem or the flowers will be too fragile to survive.
Prepare Food Coloring
Mix your dyes of food coloring and water. Use a good amount of dye (10 to 12 drops) so that the pigment will be saturated enough to really color the petals.
To get the full rainbow, use red, blue, and yellow dyes. They will probably mix a bit on their way up each stem, creating the full rainbow effect and making each rose a little bit different.
Place Roses Into the Dye
Each color dye will go into its own narrow container, such as bud vases or test tubes. Place sections of each stem into the different containers. Be gentle when bending the stem sections apart as you place them into separate containers. Try not to leave them exposed to air and drying out for more than a few minutes.
You could also use plastic bags filled with dye and attach one to each stem section with rubber bands. That way you can stand roses up in a single larger container. That will minimize the bending of the cut stem sections.
Store Roses Away From Sun
Leave each stem section in the dye mixture for several days.
Place the roses out of direct sunlight while they are absorbing the dye. The cut flowers are already under stress, and extreme heat or light will weaken them further.
Keep Roses Hydrated
Now be patient. You may notice the petals changing color within a couple of hours, but leaving them in the dye for up to a week will result in the most dramatic colors. Make sure the roses are not left sitting in dry containers once the water/dye solution is all absorbed.
Finish Trimming the Stems
Once the desired effect is obtained, you can cut off the split section of the stems and place your roses in a vase of fresh, room temperature water and enjoy.
Monteiro, António A.; Lopez, Roberto; Janick, Jules (2008). “Gilding the Lilies: Rainbow Roses and Confetti Poinsettias“. Chronica Horticulturae Vol. 48, No. 1. International Society for Horticultural Science.