Whether or not that old packet of seeds will germinate is a question that often arises in gardening. But when the seeds in question have taken a trip to the International Space Station (ISS), the answer gets a bit more complicated. In 2015, a million rocket (AKA arugula) seeds blasted off to spend six months in space. When they returned to Earth in 2016 they faced an even larger challenge – they were to be sown by a horde of little fingers as the RHS Rocket Science experiment turned school children into space gardeners!
Announced at the RHS Chelsea Flower Show in 2015, Rocket Science was part of Tim Peake’s Principia mission to the ISS. For 35 days children nurtured and monitored two sets of rocket seedlings. One had been to space, and the other had stayed on Earth. Would they be able to tell the difference? The RHS collected and analysed the results, and published their Rocket Science: Our Voyage of Discovery report in November 2016. Their key finding was that there was a small difference, with the space seeds being slightly slower to germinate.
Scientists at Royal Holloway took over and carried out experiments in controlled conditions to find out why there might be a difference in germination time. They confirmed that the space seeds are slower to germinate because they had been aged (damaged) by their trip into space. Once the dry seeds are watered they can repair the damage, but doing so leads to a slight delay in germination. Once the seeds have germinated, they can grow as normal.
If you want to know more you can read the press release from Royal Holloway, or tackle the paper that has been published in the scientific journal Life: Rocket Science: The Effect of Spaceflight on Germination Physiology, Ageing, and
Read more on theunconventionalgardener.com