Blue roses were traditionally created by dyeing white roses, since roses lack a gene to produce delphinidin, the primary plant pigment that produces true blue flowers. So-called "blue roses" have been bred by conventional hybridization methods, but the results, such as "Blue Moon" are more accurately described as lilac in color. However, after thirteen years of joint research by an Australian company Florigene, and Japanese company Suntory, a blue rose was created in 2004 using genetic engineering. The delphinidin gene was cloned from the petunia and inserted into a mauve-blend rose, the Old Garden Rose 'Cardinal de Richelieu' (a Rosa gallica). However, since the pigment cyanidin was still present, the rose was more dark burgundy than true blue. Further work on the rose using RNAi technology to depress the production of cyanidin produced a mauve colored flower, with only trace amounts of cyanidin.
Blue roses traditionally signify mystery or attaining the impossible. They are believed to be able to grant the owner youth or grant wishes. This symbolism derives from the rose's meaning in the language of flowers common in Victorian times.
According to a Chinese folktale, the blue rose signified hope against unattainable love. There are various versions of this story that can be found online.
In the play The Glass Menagerie, the sister in the play was ill with "pleurosis" or pleurisy as a teenager. During a scene a former classmate tells her that he interpreted the word as "blue roses", which became his nickname for her.
In the book series A Song of Ice and Fire, blue roses are used to symbolise the character Lyanna Stark.
Peter Straub has written the Blue Rose Trilogy, consisting of Koko, Mystery, and The Throat. Blue roses are also a key part of one of the events described in his short story "Bunny Is Good Bread", which depicts the childhood of Fielding "Fee" Bandolier, one of the characters who appears in the Blue Rose Trilogy.