The title of this post conjures up a horrible idea! What’s wrong with flowers being the colour they have always been? Yet for centuries the world has been trying to find new colours [and indeed shapes, sizes and almost any other feature you care to name] and if they can’t be found then manipulate them into existence, first by natural selection, then by deliberate hybridising and most recently by genetic means. Nowhere is this more true than in the case of the blue rose.
However maybe it is worth remembering in the Victorian language of flowers, blue roses meant a quest for the impossible or unattainable! Will 21stc science change that?
I suppose the first question to ask is who on earth wants a blue rose? One who definitely does is Charles Quest-Ritson, author of the RHS Encyclopaedia of Roses. Writing in Country Life in 2019 he argued “The possibilities are enormous. Imagine gentian-blue Floribundas in flower throughout the summer and autumn. They would revolutionise our gardens, as did Soleil d’Or, which is the ancestor of every yellow or orange rose in our garden today. Bring on the blues, say I.” But interestingly he admitted that most rose lovers wouldn’t agree with him, and those I’ve shown the draft of this post were pretty negative about the idea. These days with gene manipulation could it ever be a possibility?
Just a word of warning. The next few paragraphs are about the science of flower colour so if you’re more interested in the history of the blue rose – and the pretty pictures – then just skip through them.
Of course it’s not just roses that are limited in colours: there are no blue dahlias or camellias, scarlet crocus or delphiniums, or yellow verbenas or African violets. In fact less than 10 per cent of the world’s 280,000 flowering plants produce blue flowers, which may be why they’re often a symbol of the unattainable in folklore and literature. There are good scientific reasons for this as is explained in a short video clip by Dr Helen Czerski for the BBC. It’s all about the chemicals that create the pigments in the petals. Keeping it all as simple as possible there are two major classes of flower pigments: carotenoids and flavonoids. Carotenoids include carotene pigments which produce yellow, orange and red colours, while Flavonoids include anthocyanin pigments which produce red, purple, magenta and blue.
Plant families usually only have pigments derived from one of the major sets, which limits the colours they are able to produce. It was long thought impossible for any plant family to have flowers of all three primary colours – red yellow and blue – within its ranks. After intensive hybridisation a few families such such as hyacinths come close but the “yellow” is pale and washed out, more off-white than golden, while the “red” isn’t a true red either. Plants in the “new” colours also have a tendency to be weaker.
But as Dr Czernin shows some of these pigments, such as delphinidin, [one of the flavonoids which is the cause of blue colouring in delphiniums] is like litmus paper, and also acts as an indicator of acidity/alkalinity. You can relive your schooldays by doing an easy experiment to prove that, either by repeating what she did in the video using red cabbage or by crushing red rose petals on a white plate with the back of a spoon and then adding either vinegar or baking soda and watching what happens to the colour. What they show is, believe it or not, that red rose petals are acidic and so even artificially adding blue pigments only creates a muddy purple colour or as we see later at best a lilac or lavender shade.
Of course it’s much more complicated than that in reality – and much too technical for me to either understand fully myself or try to cover here so, if you want to really understand how and why flowers are the colour they are take a look at this article from the Library of Congress which also has links to other sources of information.
Now let’s turn to blue roses in history bearing in mind that Victorian sentiment that blue roses symbolised the impossible.
Really? Impossible? How does that account for the fact that a blue rose was recorded in mediaeval arabic texts from Southern Spain. Given what I’ve just said that might sound unbelievable but actually the same sources also told of yellow roses, which were also at the time, and indeed until they were imported from Persia in the early 17thc, equally unknown in western Europe. Maybe the Moorish writers knew something western Europeans didn’t? Later in 1752 a French gentleman scientist, the Marquis d’Orbessan read a paper about roses to the French Academy of Sciences claiming that he’d seen blue roses growing quite abundantly in a village near Turin. So perhaps blue roses were not impossible merely an extreme rarity?
The only way of getting blue roses currently is by dyeing white ones
Is there another explanation? Well it turns out that the mediaeval agricultural writer Ibn al-‘Awwam was reporting, in great detail , what he had been told about some experiments to change the colour of roses. This involved cutting into the root system and inserting saffron under the “skin” of the root to produce yellow roses, or if blue roses are wanted then “falch, a brilliant indigo should be used.” He also recounts, with tongue somewhat in cheek, that “a citizen of Damascus… dissolved indigo in water” and watered the plant with it throughout the winter to get blue roses. When this story was retold by Samuel Parsons in The Rose: its History, Poetry, Culture and Classification in 1847 whilst he questioned its accuracy he did think it could be the basis for some experiments. After all it was known that pink hydrangeas could be turned blue by altering the acidity of the soil. If it seems like a flight of conjecture to have blue roses Parsons reasoned that after “the recent invention of the Daguerrotype” and “the magnetic telegraph … nothing can be deemed impossible or incredible.” Perhaps argued some it was simply “a mark of imperfect evolution.”
The desire for the blue rose has long been there. In 1810, for example, Lord Milford imported a consignment of what was hoped would be Blue Roses from China. They were sold by James Colville’s nursery in Chelsea – before they flowered of course – for a guinea each. Andrews noted but “such is the fascinating force of novelty, which even in embryo has the power to charm. This rose of expectation, when its blooms unfolded, no heavenly blue disclosed, but a red purple, which as it faded off became much paler, less brilliant, but of a blue or colder purple”. Looking at the image that’s hard to credit.
The hunt for celestial blue roses led, all through the 19thc, to many experiments with such ideas as watering with cobalt or copper sulphate solutions. There were even some who claimed they’d finally achieved the holy grail of the blue rose – although of course they were stretching the idea of “blueness” as we’ll see. Indeed the very idea of what can be classed as blue seems pretty flexible. Of course as you can tell by these photos of the Gallica rose Cardinal Richelieu, a lot depends on the light, the age of the flower and the quality of the photographer!
These are all images from reputable nursery sites of Cardinal de Richelieu introduced in the 1840s
Nevertheless there were a lot of developments in roses from the mid-19thc onwards. One of the earliest hybrids to be ascribed any blue quality was a Gallica rose named Cardinal Richelieu introduced in the 1840s which has a changeable purplish red colour. It was to play a part in later attempts to create a blue rose. An article “Roses of the Future” from 1878 looked at the progress towards a blue rose over the previous 40 or 50 years. Fifteen were listed ranging from “Bella Villaresi” described as a full light purple, through “King of Saxony” a deep lilac to “Beauty of Monza” pale purple and often marbled with a deeper shade and “Violet Bengal” which had purple flowers. [Most of these are now unknown or unavailable.] So the article concluded that there had been sufficient material to get closer to a true blue rose, and suggesting that these violet coloured ones should be crossed with the “the bluest tinged of our present dark-purple crimsons and vice versa.”
The author, WD Prior, then went to describe a newish rose Reine des Violettes, introduced in 1860 “as excellently adapted for this course of experiment”. Because it was not a big blowsy flower it had been largely dismissed by English growers but was still obtainable in France, along with Ardoisé de Lyon [bred in 1858] which had apparently “a slaty-bluish flush upon the petals” although looking at the modern photos you’d be hard pressed to see that.
A later article by rose breeder George Paul in The Gardening World in June 1891 described new rose introductions post 1860 – but there is no mention of anything remotely blue. Yet when I did a check on the really useful helpmefind.com website which has a database of roses there were 36 pre-1850 introductions and a further 15 1850-1899 introductions which had blue somewhere in their description.
Veilchenblau – lovely though it might be calling it blue doesn’t seem right
Gardeners Chronicle 6th Feb 1858
There were occasional press reports of someone breeding blue roses but all turned out to be exaggerations at best. That did not stop unscrupulous nurserymen, or rather unscrupulous con-merchants posing as nurserymen, selling plants [not in bloom of course] labelled blue roses. For example, Gardeners Chronicle reported a party of Frenchmen, posing as Giraud & Co touring Wales in the 1850s selling all sorts of bogus plants from an illustrated catalogue. It was clearly a profitable business since around the same time another French group took a shop in Regent Street in London’s West End for a few months and “professed to sell colossal Pears, blue Roses and all the rest of the bogus family.” Similar stories were regularly reported too from New York and other major American cities. The gullible were everywhere.
In commercial terms, however, its not really until after the turn of the 19th/20thc that we see the arrival of what many nurserymen were describing as a blue rose – albeit as “steely blue” or “violet-blue”rather than “cornflower”. This was “Veilchenblau”, a seedling from “Crimson Rambler” bred in Germany probably before 1909. According to one catalogue although “no one pretends that it is the last word in blue roses… It may be fairly described as an epoch- making variety.… It is a new freak among roses, and quite distinct… Perhaps the most novel creation of the century.” While for another it was simply “the best we yet have in blue roses.” A few catalogues , like the one below, stretched credibility beyond belief with another describing Veilchenblau as “exquisitely cornflower blue“. I’d suggest you don’t buy roses from a colourblind nurseryman like them!
But for a plant that was clearly thought to be a bit of a game-changer it was already being sold cheap at just 25c the year after its introduction. It served another purpose too often being sold alongside a white and a red rambler so gardeners could create a patriotic display!
Lack of any real colour breakthrough seems to have led to a decline in further attempts until the 1950s and 1960s when dozens of new “silver” and “lilac” roses were introduced, with names like Blue Moon, Blue Dawn or Rhapsody in Blue, helping them pretend they were the real thing. You can check just how many at helpmefind.com.
Everything changed – in theory at least – in 2008.
An Australian-based subsidiary of Suntory, a Japanese company claimed to have achieved the impossible and produced a blue rose which they named Applause. It was put on display that year at the International Flower Expo in Tokyo, the world’s largest flower and garden trade show alongside other delights such as glow-in-the-dark roses which had been genetically modified to light up in the dark.
Work had started on the blue rose project as early as 1990 by trying to isolate blue genes from dark purple petunias . But they had a shock when they introduced these petunia genes into red roses through tissue culture on an industrial scale. When the roses flowered they remained resolutely red. Roses clearly were rebels and refused to be converted!
However the same process did succeed in producing what they called “blue” carnations. They became the world’s first genetically modified cut flowers and are now in commercial production, although not in Europe. They also discovered that the process is an evolutionary dead-end because these flowers hardly produce any viable pollen, effectively making them sterile.
Another Japanese company performed similar tricks on chrysanthemums, the world’s second best-selling flowers after roses, releasing a range of “blue” varieties in 2017. [Not sure why but they seem much more acceptable/realistic in terms of colour than either the carnations or roses.]
After their failure with petunia genes Suntory started isolating genes from other plants with bright blue flowers but with equal lack of success until in 1996 they tried genes from blue pansies. These made the red roses slightly darker but still not anything like blue. More experiments, on more varieties of roses including Cardinal de Richelieu that we saw above pushed the colour change further and they switched to vegetative propagation and from 2002 began grafting the bluest of their selection onto rootstocks.
Even so, roses [like the carnations and chrysanthemums] could not be grown outside laboratory controlled conditions because they were genetically modified, so more experiments had to be done crossing the modified roses with wild species to prove that there was no risk of spreading the introduced genes among wild roses.
Permits were finally obtained in 2008 to grow plants in Japan and Applause was finally released as a cut flower in Japan 2009 and two years later went on sale in America 2011 at £15-20 for each stem. But the whole scheme seems to have flopped rather spectacularly perhaps because the rose seemed to have had a short vase life. After further “selection” Applause was re-introduced to the US market in 2017. They are not available in Europe or the UK.
Interestingly the Suntory webpages about Applause, has not been updated for about 10 years, so its unclear whether work is continuing to create a cornflower-blue rose, although they did release a short video on YouTube about Applause and its development in 2019.
And if the poor rose hasn’t suffered enough scientists at Tianjin University and the Chinese Academy of Sciences have been working on a different method of creating blue roses, using bacterial enzymes which somehow converted “L-glutamine, a common constituent of rose petals, into the blue pigment indigoidine” which was injected into the rose. A blue tint spread from the point of injection it doesn’t last long The next step is to engineer roses that produce the two enzymes themselves, without the need for injections so that the effects are permanent. The team published its results in the Synthetic Biology journal of the American Chemical Society.
It all seems an awful lot of trouble for something awful- although there’s doubt it will make someone an awful lot of money! Poor roses!
The Gardens Trust 
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