In April 2021, a handful of people met under cover of darkness in East Lansing, Michigan. Midnight had come and gone hours ago, but dawn was still a long way off. They were outside, where it was bitterly cold, and then it began snowing. They moved quietly, carrying shovels and torches. One of them, the eldest, also carried a map. He was the only living person to have seen what they were looking for, the only one who knew where it was. A lot of time had passed since he was last here, though, twenty-one years, and the map was old. Not everything looked precisely the same as it once did, so it was easy to lose one’s bearings. The darkness and the snow weren’t helping, either.
When at last the group reached the agreed spot, they began to dig, but they didn’t find what they were looking for. It was not the right place. They conferred in hushed tones, reoriented themselves and tried again. They hit something, but it turned out to be a tree root. A little while later, someone pushed a spade into the snow-damp ground, moved the dirt away, first with tools and then with their hands, and they felt something hard, but it was a false alarm. Just a rock. Now they were not just cold and tired but muddy, too, and dawn was edging closer. They were getting worried because what they were doing required darkness – among other things, it’s important they weren’t seen, not by anyone. Sworn to secrecy, none of the group would tell another soul where they had been that night, not for years.
Then, just as hope was beginning to fade, someone reached into a freshly dug hole and her fingertips brushed against something solid, smooth and curved. It felt like the neck of a bottle. At first she wasn’t sure, then she was. She called out to the others and a few minutes later she had it in her hands: a bottle that was buried 142 years ago. It contained seeds.
Back in the 1870s, a botanist at Michigan State University (MSU) by the name of William J Beal noticed how weeds seem to grow in farmers’ fields year after year, despite all efforts to remove them – efforts that were often made before the plants in question had a chance to produce seeds. So, where were all these weeds coming from? Beal knew that many plants drop seeds into the soil, forming what is now known as a soil seedbank, a long-term cache, and that only some of the population will germinate each year, with the remainder germinating in subsequent years. But that raised the question of how long those seeds could last. Was it two years? Ten? Hundreds? Beal didn’t know the answer, no one did, so he decided to try something. He later wrote in the Botanical Gazette:
In the autumn of 1879, I began the following experiments, with the view of learning something more in regard to the length of time the seeds of some of our most common plants would remain dormant in the soil and yet germinate when exposed to favourable conditions.
He went on to describe how he had collected seeds from twenty-three plant species and varieties, including a selection of weed species, precisely because they seemed so tenacious. He took fifty seeds of each species, mixed them with sand, and placed the mixture into a glass pint bottle. He repeated this process twenty times so that, in the end, he had twenty identically filled bottles. Then, carefully choosing a location on the expansive grounds of Michigan State University, he buried them, ‘uncorked and placed with the mouth slanting downward so that water could not accumulate about the seeds’.
Five years later, Beal returned. He dug up one of the bottles, removed the seeds and planted them. Over 250 germinated, but only from twelve species. The others, it seemed, had already passed their use-by date. After another five years, he repeated the process: one bottle exhumed, one lot of seeds planted, more data recorded. He continued this process every five years thereafter. By the time of his death in 1924 he had collected forty years of data, but there were many more bottles to go. Before he passed away, Beal revealed the location of the bottles to a younger colleague, botanist HT Darlington, who then exhumed one bottle every ten years – he had decided to stretch things out a bit. When the time came, Darlington passed the baton to yet another younger colleague. And so on. As time went on, fewer seeds germinated, and little by little species dropped out of the game. As the end of the 20th century approached, it was decided to stretch the intervals to twenty years.
In the year 2000 another bottle was unearthed, this time by MSU botanist Frank Telewski, the seventh keeper of the seeds. He planted them and observed which ones germinated. It seemed there were only one or two species left standing. The calendar was duly marked for twenty years hence: April 2020. As the date approached, Telewski selected a team of biologists and ecologists to become his successors and invited them on his second and final dig. The Beal Bottle Experiment is the stuff of legend at MSU, so Marjorie Weber, David Lowry, Lars Brudvig and Margaret Fleming were all thrilled to be tapped on the shoulder. But when April 2020 finally rolled around, the dig had to be called off courtesy of the COVID-19 pandemic. The state of Michigan was under strict stay-at-home orders, and the campus was off-limits to all but essential personnel. The experiment was delayed, then delayed again. At last, one year later, Telewski, Weber, Lowry, Brudvig and Fleming set out at 4 am in the snowy darkness. That darkness was key not just for secrecy – no one wanted to risk exposing the bottles to daylight on the off-chance it might trigger germination in any of the remaining seeds and muck up the long-term experiment.
Tired and muddy yet victorious after retrieving their prize, the Beal team brought the bottle to the lab where they spread the seed– sand mixture onto a large shallow pan filled with sterile potting soil, watered it, and placed it in a well-lit growth chamber. Days passed and nothing happened, but that, they all knew, is ever the nature of seeds – even healthy ones can take their sweet time. Even so, it was hard not to wonder if perhaps Beal’s experiment had reached its end.
It was on 23 April 2021 that the first tiny seedling began to emerge. Soon there was another, and another. By June, more than a dozen had popped up, all from the same species: Verbascum blattaria, a small flowering member of the figwort family and considered an invasive weed in North America. Certainly, it’s tenacious – just as Beal suspected. These seeds had been collected 142 years earlier and they were still alive.
The Beal Bottle Experiment is slated to continue until the year 2100, and perhaps V. blattaria will still be germinating at that time. Hard to say. In the meantime, the team are planning Beal 2.0, a larger experiment with similar seeds but with more of them, so that the project can last much longer than the first one. There are also enough seeds for planting as well as spares for experimentation, because everyone wants to know what’s actually going on inside the old seeds. Indeed, Beal wasn’t the only one to wonder about this.
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‘The problem of longevity of seeds has not been solved as yet,’ wrote plant physiologist Frits Went and botanist Philip Munz in the late 1940s. Though William Beal and others had begun investigating seed life spans under natural conditions – Beal, for example, having stored his bottles uncorked in the ground – Went wondered how long seeds might last under ideal conditions. Exactly what constituted ideal conditions was a matter of debate but it was clear by that point that metabolic respiration was a significant factor in a seed’s ageing process. Went reasoned that storage in the absence of oxygen might extend a seed’s life span considerably. It was definitely worth a shot, so in 1947 Went designed an experiment that would far outlive him.
Plant physiologist Christina Walters knows the story well. ‘It’s a great experiment!’ she tells me, explaining that with the help of Munz, Went collected the seeds of more than ninety species native to California. They were placed into ‘the most beautiful glass vials’ which were then vacuum-sealed, she says, adding: ‘They have a nice little piece of paper in there that gives the reference number as well as the genus.’ Twenty batches of these ninety-plus vials were prepared, each wrapped in brown paper, marked with its opening date, and left with instructions that the vials were to be opened on that date and planted, and the outcome recorded. It was all placed in a seed storage room at the Rancho Santa Ana Botanic Gardens in Claremont, where Munz was director. It was not cold storage, mind you, but the ambient temperature in that room never varied much beyond 10–20°C regardless of the season. The first batch was opened a year later, in 1948, then at ten-year intervals for a few decades, with plans thereafter to extend the interval to twenty years. ‘It’s a lot of time capsules,’ says Walters.
Things were going well until, in 1987, the time came to open a batch and it was discovered that the seeds had gone missing. It seems at some point in the preceding two decades, someone who hadn’t known of the vials’ importance had either disposed of them or moved them. Fortunately, three years later they were found elsewhere in the gardens. The seeds were brought to the National Laboratory for Genetic Resources Preservation in Fort Collins, where they remain today. Walters is the current successor/custodian of the Went project, which she finds fascinating. She tells me that the paper inside the vials is beginning to turn brown and that even this is useful information: ‘The seeds are ageing, the paper’s ageing.’
The last batch was opened in 2014, Walters tells me. In a nod to the project’s history, she invited people from Rancho Santa Ana, which is now called the California Botanic Garden, and they staged a little ceremony and together carefully opened each vial. ‘You have to use glass cutters,’ she says, then laughs. ‘Who has glass cutters anymore?’ There were as many as 300 seeds in each vial, enough to collect good germination data, with plenty spare for other experiments.
‘A lot of the agricultural seeds are not alive,’ Walters says. Most of those are grasses, and even in vacuum-sealed tubes they’ve rotted. It isn’t pretty. ‘Dead seeds are not beautiful to see,’ says Walters. Some other species are beginning to falter, too, though not quite so dramatically. Their longevity appears to be falling largely in line with family or habitat and some of these results have been outlined nicely in Save Plants, a publication of the Center for Plant Conservation. For example, seeds in the primrose family are faring better than those in the sunflower family, with more of the former germinating each time than the latter. Curiously, seeds from woodland species appear to be living longer than seeds from desert species.
Some species, however, are doing astonishingly well. Walters’s favourite is an endemic Californian wildflower called clarkia. ‘You remove it [from the vials] and two days later on water, 100 per cent of the seeds germinate!’
The whole thing is scheduled to finish in the year 2307.