Have you seen a rainbow rose? It’s a real rose, grown to produce petals in rainbow colors. The colors are so vivid, you may think pictures of the roses are digitally enhanced, but the flowers really are that bright! So, you may be wondering how the colors are made and whether the rose bushes that produce these flowers always bloom in vibrant colors. Here’s how it works and how you can make a rainbow rose yourself.
How Real Rainbow Roses Work
The “rainbow rose” was developed by Peter van de Werken, the owner of a Dutch flower company. While special roses are used, the plants are not bred to produce rich colors. Actually, the rose bush would ordinarily produce white roses, but the stems of the flowers are injected over time with dyes so that petals form in bright single colors. If the flower isn’t treated as it is growing, the blooms are white, not rainbow. While the rainbow is a special version of the technique, other color patterns are also possible.
It’s not a science trick you can achieve quite so well with your home rose bush, at least not without a lot of experimentation and expense, because most pigment molecules are either too large to migrate into the petals or else too toxic for the rose to flower. Special proprietary organic dyes said to be made from plant extracts are used to color the roses.
Making Rainbow Roses at Home
While you can’t duplicate the exact effect, you can get a lighter version of a rainbow using a white rose and food coloring. The rainbow effect is much easier to achieve with white or light-colored flowers that aren’t as woody as a rose. Good examples to try at home include carnations and daisies. If it has to be a rose, you can do the same project, but expect it to take longer.
Start with a white rose. It’s best if it is a rosebud because the effect relies on capillary action, transpiration, and diffusion in the flower, which takes some time.
Trim the stem of the rose so that it is not extremely long. It takes more time for the color to travel up a longer stem.
Carefully split the base of the stem into three sections. Make the cuts lengthwise up the stem 1-3 inches. Why three sections? The cut stem is fragile and likely to break if you cut it into more parts. You can use color science to achieve the full rainbow using three colors—red, blue, yellow or yellow, cyan, magenta—depending on what dyes you have available.
Carefully bend the cut sections slightly away from each other. Now, one way to apply the dyes would be to bend the stems into three contains (e.g., shot glasses), each containing a single color of dye and a bit of water, but this is hard to accomplish without breaking the stems. An easier method is to use 3 small plastic baggies, 3 rubber bands, and one tall glass to hold the flower upright.
Into each bag, add a small amount of water and several (10-20) drops of one color of dye. Ease a section of the stem into the bag so that it is immersed in the dyed water, and secure the bag around the stem with a rubber band. Repeat the process with the other two bags and colors. Stand the flower in a glass. Check to make sure each stem section is immersed in the liquid since the flower needs water to live.
You may start to see color in the petals as quickly as half an hour, but expect to let the rose soak up dye overnight or possibly for a couple of days. The petals will be the three colors, plus the mixed colors, for petals receiving water from two parts of the stem at once. This way, you’ll get the whole rainbow.
Once the flower is colored, you can trim off the cut section of the stem and keep it in freshwater or a homemade flower food solution.
Flowers take up warm water more quickly than cold water.
Keep the rose away from light and heat, since these can cause it to wilt and die too quickly.
If you want to try injecting flowers with natural colors, learn about natural pigments you can use.
By Anne Marie Helmenstine, Ph.D