Do plants know we're here?

CrowdScience listener Gurmeet in India wants to know if plants can sense that we're around. She started wondering about this at a wellness centre where she was encouraged to hug a tree. She enjoyed the experience, but what about the tree? Did it enjoy being touched? And is there actually evidence that hugging a tree is good for us? Anand Jagatia talks to scientists about what happens to a plant when it's touched. Molecular biologist Olivier van Aken, from Lund University in Sweden, explains what happens inside a plant's cells – from mimosa whose leaves close up when touched to a Venus flytrap that sees a good opportunity for dinner. Plant biologist Alexander Jones, from the Sainsbury Laboratory at the University of Cambridge, UK, tells Anand how plants process information without a brain: when there's a threat from a hungry insect, it's their hormones that leap into action to defend it. Anand visits Wisley Garden in the UK and meets Ashby Lavelle Sachs, the Royal Horticultural Society's Wellbeing Fellow, who explains why being in nature is so good for our physical and psychological health. And he talks to South Korean researcher Sinae Park, from Konkuk University in Seoul, about the impact of touching plants with different types of foliage – in an experiment, she found that it's the soft and smooth plants that made participants feel most relaxed. It turns out that plants find the whole experience of being touched pretty stressful. So next time you hug a tree, you might be getting a whole lot more pleasure out of it than the tree does. Presenter Anand Jagatia Producer Jo Glanville Editor Ben Motley (Photo- I love you nature! Nature and people - stock photo Credit: Kieferpix via Getty Images)