Roses are red.

Violets are blue. But researchers want the inverse to be true.

Okay sorry, that was cryptic. Let me explain. Remember how in 2020, we were all  playing a ton of Animal Crossing?

There were all the different types of flowers that you could cross-breed to make new colors. For just about all the types of flowers,  unlocking the blue ones was pretty easy. But getting the blue roses was insanely hard.

As it turns out, that’s one of the many ways that Animal Crossing designers made  their game just like real life. Outside of video games, there are  more than 30,000 cultivars of roses, and people have bred roses in all  kinds of shapes, sizes, and colors. But no one has ever managed to grow  a rose with naturally blue petals.

And the people who want it, want it bad. Like, people have poured millions of dollars into breeding a true-blue  rose, without very much luck. Here’s the bizarre, decade-spanning story of science’s failed attempts at making blue roses. [♪ INTRO] Roses are a big deal.

Since their domestication around 5,000 years ago, roses have been prized for  everything from their beauty, consumed in tea or desserts, used as medicine, and given to the contestants on The Bachelor  when they make it to the next round. At least I think that’s what happens. I don’t actually watch The Bachelor.

Today, the rose industry is worth roughly  $5 billion a year on the global market. People have kind of always been into roses. But the rose obsession really  took off in the 19th century, when European gardeners started  breeding new varieties like crazy.

And one thing people wanted  to do was to grow blue roses. There is, of course, one really  simple way to get a blue rose. And that’s to take a white rose and dye it blue, usually by sticking the cut stem  in water with blue dye in it.

But that solution wasn’t good enough for Big Rose. They wanted to breed a real,  100% certified genetic blue rose. There’s just one teensy problem with this.

It's not physically possible. Most wild roses come in just three  colors: white, pink, and red. These colors are generated by  natural pigments called flavonoids, which the plant keeps in handy  little sacks called vacuoles.

Rose breeders can cross-breed roses with  different flavonoids to get new combos, and make all the other shades we might see. To make a naturally blue  rose, you’d need your plant to produce some sort of blue pigment. And roses just don’t do that.

They’re not alone. Less than 10% of all flowering plants are blue. See, blue pigments tend to be complicated to make and even harder to maintain inside living cells.

Most animals that look blue don’t  even bother making pigments. Instead, they’ve evolved  these molecular structures that let them reflect blue out into the world. That said, there are some plants that  can get around the blue pigment problem.

But their blue pigments are super  sensitive and break down easily, and if the pH of the vacuole  is off even a little bit, your blue pigment turns not-so-blue. Since it’s such a fiddly process,  it makes sense that flowers only evolve the ability to go blue if  there’s a really good evolutionary reason to, like being more visible to pollinators in a crowded ecosystem, or something like that. And roses just never had that  pressure, hence, no natural blue roses.

But wait! It’s 2026. We can make worms glow by giving them  jellyfish genes and put robots on Mars.

Surely science can turn some flowers blue! And yeah, people have been using  genetic and molecular engineering to try and make a blue rose  happen since at least the 1990s. One major player is the Japanese  beverage company Suntory.

In 1990, Suntory partnered  with an Australian company Florigene to try their hand at growing blue roses. The idea was simple. Take genes from plants that make the  coveted blue and stick them into roses.

To do this, researchers  hired by the company decided to focus on the blue pigment in petunias. Like most blue-ish plants, petunias make  a type of blue pigment called delphinidin. Delphinidins are made when specific enzymes tweak certain flavonoids, making them blue.

Step one was finding the genes  behind this transformation, which Suntory did in 1991. Then, all they had to do was  stick them into roses’ genomes so the flowers could start  making their own blue pigment. At least, that was the theory.

Researchers grew a bunch of  roses with the new enzyme, but none of them were very blue. So they tried genes from other plants. Still, nothing.

They knew they  must be missing something, and it turned out to be pretty basic: pH. If you’ve ever grown hydrangeas,  you know the flowers change color depending on how acidic the soil is. Turns out, that’s also true for roses.

Roses that had delphinidin in an overly  acidic environment would just turn red. But in a way, this was a good thing,  since now they knew that all they needed was to grow roses with a higher pH to  prevent the delphinidin from going pink. Finally, in 2004, the researchers announced that they’d successfully made a blue rose.

They called it SUNTORY ‘blue rose’  APPLAUSE and put it on the market. The rose made headlines, won an award, and was displayed in the National  Museum of Nature and Science in Tokyo. But as critics would point  out, despite a decade of work, APPLAUSE is not super blue.

As one 2018 paper puts it, Suntory’s  rose “is indeed of mauve color.” So while it is true that APPLAUSE is  the only rose that makes a visible blue pigment, that still hasn’t given us the  true blue hue that we’re all dying for. But people still aren’t done using  science to do the blue rose thing. In 2018, a group of Chinese researchers announced that they had made a rose with  blue petals, with bacteria.

Since adding the delphinidin  molecule to roses was a non-starter, if we’re going to get our coveted blue  roses, we need a different molecule. But like we said, naturally  occurring blue pigments are rare, so there weren’t many other options  in the plant world to pick from. Fortunately, we don’t have to  limit ourselves to just plants.

Some microbes make a blue  substance called indigoidine, another blue pigment that the researchers hoped would get them closer to the perfect blue roses. And no, getting the indigoidine  into these roses wasn’t easy. The researchers needed to make a whole new genetic package that combines  rose and bacteria DNA.

Most of the time, getting a non-bacterial  cell to make the kinds of enzymes that bacteria use is challenging, because  the enzymes are just too darn big. But lucky for them, the enzyme for  indigoidine is smaller than a lot of others, so when the researchers isolated it to  introduce it into the roses, size was no issue. So to get around that issue,  the researchers had to find a smaller version of the gene, engineer  a bacterial line that’d plop the gene into the rose DNA, and inject those  modified bacteria into white roses.

And good news, it worked! After 12 hours, the team saw patches  of blue appear on the rose petals, right where the needles had gone in. These results led the researchers to announce they’d made the first biologically  engineered blue rose in human history.

Although….. I have some thoughts. To start, these roses weren’t blue all  over, and the pigment only showed up in little splotches near where the  petal was injected with the bacteria.

Plus, the color doesn’t stick around  forever, so even if they managed to make the whole thing indigo blue, your bouquet  would fade back to white pretty fast. It could also be argued  that this technique is just a high-tech version of dyeing a rose. After all, you aren’t really changing  its fundamental biology, are you?

As far as we can tell, these  researchers haven’t published anything more on their quest for blue roses, so whether bacteria are really the  key to blue roses remains to be seen. So science is now 0-2 on  the whole blue rose thing. It’s kind of like, ‘Stop trying to make a  blue rose happen.

It’s not going to happen!” Which actually brings us to a  pretty fundamental question. Why are we even doing this? Why spend years of your  life and millions of dollars trying and failing to make a rose blue?

For companies like Suntory, one  aspect is undoubtedly financial. When they first put the  APPLAUSE roses on sale in 2009, reports say that the company was planning  to sell them for around $30 per stem, making their roses about ten times  more expensive than regular roses. But it can’t be true that everybody involved in making blue roses is in it for the money.

Humans value beauty and novelty. We want to create something  new, something unimaginable, a thing that seems impossible. And that’s exactly what a blue rose might be.

If we do ever manage to genetically engineer one, that pinnacle of both science and aesthetics… Well, I guess they’ll have to make some  changes to the Animal Crossing games. [♪ OUTRO]