Climate change threatens Dutch tulips

The Netherlands are getting warmer - and tulips do not like that. The beloved flower is dealing more and more often with soft winters and capricious springs. Can science protect this Dutch icon from the consequences of climate change?

4 billion flower bulbs per year

Each spring, the Netherlands turn into a living painting. Large fields colour yellow, red and pink as soon as the tulips are in bloom. These colourful carpets are famous all over the world: as a tourist attraction, as a picture post card, as an icon of the Dutch landscape. Annually, our country produces over four billion flower bulbs, half of which are exported. But the enchanting image is shaking. Because of climate change, the future of the tulip is coming under pressure — and a piece of the Dutch identity along with that future.

I discovered I'm allergic to tulips, but I can't resist researching them.

The heart of the tulip

Manuel Aguirre-Bolaños knows the vulnerability of flowers like no other. The Mexican biologist, with ties to Utrecht University, started his career with protecting endangered orchids. Since a number of years, he focuses on tulips, and not without personal consequences. “I discovered I'm allergic to tulips,” he says dryly. “But I can't resist researching them.”

What fascinates him is not the flower, but the bulb under it. “Because although the Netherlands are leading in the cultivation of tulips, we know remarkably little about the juvenile phase (editor's note: early development phase) of the plant.” Aguirre-Bolaños wants to change that. And fast too, because the circumstances in which tulips grow best are rapidly changing.

Warmer, wetter, more capricious 

“Tulips are extremely sensitive to temperature,” he explains. “In order to form flowers properly, they need long, dry winters. If these winters stay away, the stems stay short, the flowers come out lopsided or unevenly, or they don't bloom at all.”

Exactly these circumstances are under pressure. The Dutch winters are becoming softer and wetter, while heat waves strike more and more often in the spring and the summer. The consequences are already visible: the Keukenhof, the world’s largest flower garden, now has to plant approximately thirty percent more bulbs to ensure the dazzling display of flowers visitors expect for their 21-euro tickets.

Beauty over strength

This vulnerability of tulips also has historic causes. For centuries, horticulturists have gone for appearance instead of resilience. In the 17th century, ‘broken tulips’ - with their flamed flower petals in two colours - were sold for absurd prices. The famous red-white Semper Augustus is said to have once sold for the price of an Amsterdam canal house. What was seen as a rare beauty at the time, afterwards turned out to be the consequence of a virus weakening the plants.

A tulip is like a sugar-coated baseball. Everyone wants to take a bite out of it.

Even now, the tulip is susceptible to all kinds of things: fungi, bacteria, rodents. “A tulip is like a sugar-coated baseball,” says Aguirre-Bolaños. “Everyone wants to take a bite out of it. They're beautiful, but incredibly fragile.”

Excruciatingly slow progress

In order to make the tulip more resilient to climate change, horticulturists would love to develop new, stronger variants. But that is easier said than done. Whereas a tomato plant bears new fruits in a couple of months, tulips take five to seven years before a seedling blooms for the first time. Tulips can already be tested for resistance to draught and diseases during that period, but horticulturists can only assess the characteristics which are determining for a new variant in the blooming phase. 

“The duration of the juvenile phase of the tulip (editor's note: the period before the flower blooms) is our biggest obstacle,” Aguirre-Bolaños says. “If we could shorten it with one or two years, we can respond much faster to changes in the climate.”

The key is within

The solution, he thinks, is literally in the bulb. “Every tulip has three generations of bulbs inside,” he explains. “Like Matryoshka dolls, nested together.” Research so far was mostly focused on the mature plant, but Aguirre-Bolaños believes the key to resilience is instead in the youngest, not yet fully grown bulb. “Many characteristics for future growth are already set there. By better understanding what's happening there, we might be able to accelerate the growth process AND develop stronger plants.”

Whether or not that can be done in time is still the question. But if it were up to him, tulips will still be growing in Dutch soil AND on the millions of photos made by admirers from all over the world in the future. 

Correction: An earlier version of this article misreported the price of the Keukenhof entry ticket. 

Text: Marta Jiménez Cantabrana