Since the late 19th century, botanists at the Michigan State University have been collaborating on a single seed-germination experiment. Now in its 137th year, it is turning out to be the world’s longest recurrently monitored scientific study. It will end in the year 2100, which means most of us won’t even be around for the final result.

The world’s longest-running experiment  started out in the fall of 1879, when Dr. William James Beal, a botanist, set-out to find a conclusive answer to the one question that farmers have been asking for centuries: How many times do you have to pull out weeds before they entirely stop growing back? Beal realised that to answer the question, he needed to work it out for real – by finding out exactly how long seeds could remain dormant in soil while still remaining viable.

So he devised an experiment that would, in centuries, provide the answer he was looking for. He put together a collection of seeds of 23 different plant types and decided to leave them dormant for years, before checking if they would still germinate. He placed 50 seeds of each variety in each of 20 narrow-necked glass bottles filled with moist sand, and buried them in a secret spot on the university campus.

Photo: Kurt Stepnitz/Michigan State University

According to Beal’s own writings, each bottle was “left uncorked and placed with the mouth slanting downward so that water could not accumulate about the seeds.” He also wrote that “these bottles were buried on a sandy knoll in a row running east and west.” His plan was to take out one bottle every five years and see which seeds would grow.

Beal managed to open six bottles before he retired, passing on the experiment to a younger colleague, Henry Darlington, who then passed it on to other scientists including Robert Bandurski and Jan Zeevaart. It is currently being managed by Frank Telewski, who is also the curator of the university’s botanical garden named after Dr. WJ Beal.

Dr. William James Beal/Photo: Internet Archive

Under Beal’s original plan, the experiment should have been completed in 100 years, in 1979. But a decade after his retirement, in 1920, his successor realised that the experiment seemed to be stabilizing, with the same seeds sprouting each time. So he decided to wait a decade between excavations, and his successor extended that to two decades. The latest bottle was opened by Telewski in the spring of 2000, at night, trying not to draw attention to the spot that to this day, remains a secret.

“We don’t advertise where they’re buried because we don’t want anybody poking around and digging up souvenirs,” Telewski said, speaking to Atlas Obscura. “I’m always a little nervous when there’s construction on campus. You know: ‘Don’t put a building up there!’ ‘Why not?’ ‘I can’t tell you, just don’t!’”

Dr. Telewski/ Photo: Frank Telewski

From the bottle that Telewski unearthed, only two plant species out of 23 sprouted successfully. And out of the 15 bottles removed so far, the winning species has been Verbascum blattaria, or moth mullein, a common weed in the US. 23 of its 50 seeds from Telewski’s bottle germinated, which he considers a “phenomenal” result. The other plant – Malva rotundifolia, was nowhere close, with only one sprouted seed.

While the experiment was definitely relevant in Beal’s time, when farmers didn’t have herbicides and had to resort to manual weeding, the results may not be commercially ground-breaking any more, given that modern farmers have access to several anti-weed tools. But conservationists are still interested in what the experiment has to reveal. “Many species of plants that are locally extinct may actually still be viable in the soils of those particular environments that have been disturbed,” Telewski explained. So these sleeping seeds could indeed restart populations that have been extinct for decades.

Verbascum blattaria/Photo: Arria Belli

If everything goes according to plan, the last bottle will be unearthed in 2100, but Telewski thinks it might be stretched even further. “We don’t want to lose continuity where people might forget about the study,” he said. “There’s that living memory thing that’s really important.” For now, he’s gearing up for the next excavation in 2020, only four years away, which might be the year that nothing germinates. Or, something that hasn’t germinated in the past 30 or 40 years could sprout all of a sudden. Either way, he’s excited about the possibilities.

“In 1980, I was a graduate student in plant physiology, and we learned about the experiment,” he said. “I had absolutely no idea that I would ever be the person to dig up the next bottle. And lo and behold, 20 years later, there I was… I have this wonderful opportunity to continue this historically important and significant experiment.” Meanwhile, he’s also picked out the person who could potentially inherit the experiment from him when he retires. “There’s one particular person I’ve been speaking with, and I think she’s going to be very excited to pick it up,” he told National Public Radio.

Dr. William James Beal/Photo: Michigan State University

Telewski often thinks of Beal, and other great scientists who have inspired him – Charles Darwin, Asa Gray, and even the Native American corn hybridizers. “All of us basically stand on the shoulders of giants,” he said. “It is kind of neat to be a part of that history.”

“Isn’t it wonderful that somebody, somewhere, thought forward enough to say, ‘Let’s hold onto this, let’s keep this experiment going, let’s design this experiment to go on and see where it takes us.”