The new flowers sprouting up along the busy President Kennedylaan thoroughfare in Amsterdam are not decorative. Rather, they’re experimental: these honeysuckle flowers, encased individually in plastic tubes, are being tested by a group of Dutch scientists to see how efficiently they can clear the smoggy air around them.
At the TEDxAmsterdam conference in November 2014, the Dutch engineer Ton van Oostwaard pitched a radical vision for fighting pollution in the city. The founder of the Dutch environmental organization MyEarth, van Oostwaard described how a “supercharged” honeysuckle, planted alongside Amsterdam’s busiest roads, could suck up pollution particles from the air and create “a future-proof landscape for generations to come.”
Soon after his talk, van Oostwaard sent his idea for the pollution-zapping honeysuckle to the Amsterdam Institute for Advanced Metropolitan Solutions (AMS) in response to their annual Stimulus Call for ideas to improve city life, says Emily Parry of AMS Institute. Van Oostwaard won the competition, and since January 2016, a project team consisting of researchers from AMS, Wageningen University, the City of Amsterdam, Alterra, and MyEarth has been has been collaborating to finnesse the plant; the collection along Kennedylaan is its first trial.
Called the Green Junkie, the honeysuckle has been cultivated specifically to exaggerate its air-clearing capabilities. To a certain extent, all plants act as air filters, but those that are especially “hairy,” like honeysuckles, are particularly effective, van Oostwaard said in his TED presentation. He and his team of innovative growers at MyEarth discovered that the honeysuckle is unique because it grows tiny particle-absorbing hairs on its stem, leaves, and flowers. Honeysuckles are “addicted to pollution,” van Oostwaard said, and they’re not fussy about where they grow: the flowers thrive on roadsides, balconies, and the sides of buildings alike.
So van Oostwaard started to think: what would it take for honeysuckles to improve air quality even faster than they already do? His team at MyEarth developed a custom organic fertilizer made from tree leaves and plant trimmings collected from Amsterdam’s streets, Parry says. The unique mixture of nutrients in the fertilizer activates the plant’s energy synthesis mechanisms, boosting hair growth and making them “crave” more carbon dioxide, Parry adds. The Green Junkie is still, in essence, a honeysuckle, but through van Oostwaard’s experimentation with growing conditions, it’s been given a jolt of pollution-absorbing steroids.
Fast Company reports that some grasses and ivy, planted near traffic-packed streets, can reduce nitrogen dioxide by 40 percent and particulate matter by up to 60 percent. The team currently testing the Green Junkie is hopeful that the honeysuckle will be even more effective, though Parry is careful to emphasize that the success of the plant in a lab setting may not predict how it fares in its potential “natural” habitat of central Amsterdam.
While Parry says that Amsterdam’s air quality, compared to that of other cities around the world, is far from crisis status, the city has still pledged to tackle the issue on a much broader scale, beyond vegetation. “The most effective way to improve air quality on a large scale is, without a doubt, by reducing emissions,” Parry says. To that end, Amsterdam aims to ban all cars powered by gas or diesel fuel by 2025, Tech Insider reports. The city bus fleet will transition to electric, as will garbage trucks and other municipal vehicles, and lightbulbs in street lamps and city buildings will all switch over to LEDs.
In the midst of these other initiatives, Bert Heusinkveld, an air quality researcher at Wageningen University, who’s studying the supercharged honeysuckles, told Fast Company that he’s cautious about assigning climate-savior status to pollution-trapping plants. Parry concurs. “Compared to what a drastic cut in emissions could change, the effects of the Green Junkie can seem pretty irrelevant,” Parry says.
However, she adds that the plant’s relatively small impact should not deter the city from cultivating them in areas most in need of pollution reduction. “If Green Junkie’s tests prove positive, we see great chances of incorporating the plant in both existing and new ‘green’ areas throughout Amsterdam and contributing to local air quality,” Parry says.
H/t Fast Company