You know, I am beginning to think I have a superpower, albeit one that only manifests itself in very specific circumstances. Whenever someone finds out what I do for a living, I can predict with unwavering certainty what their next question to me will be. Whether it’s in an interview with the press, in chats with cabbies, or discussions with non-botany colleagues: “So, what first made you interested in plants?” It’s a question that is almost always accompanied with a look of incredulity, and heavy emphasis on the word “plants”. Then comes: “Does it run in your family?”; “Did you have a particularly inspirational teacher at school?”; “Is it a cultural thing in Asia?” Yet no one has ever asked my football-mad big brother what it was that first caused him to take an interest in sport. Trust me, I was curious, so I called him once to double-check. It’s never instantly attributed to some kind of epiphany moment, mysterious external influence or somehow – ahem – stitched into his DNA. To me, the great irony is, I see this question precisely the other way round. I find plants so intrinsically fascinating, and have done since my earliest memories, the very idea that some people aren’t as obsessed with every aspect of them as I am is totally bizarre. After all, as a plant scientist I know that billions of years of co-evolution alongside the botanical world has directly determined every aspect of our culture, civilisation, even our basic biology. In a very real sense, plants made us human. The very way we see the world, our eyes on the front of our faces, rather than on each side like many mammals, is the result of the need for binocular vision to negotiate the three-dimensional terrain of tree canopies in our distant biological history. Our colour perception, rare in the animal kingdom, evolved to allow us to pick out easily ripe, red fruit against green backgrounds. Even in today’s concrete jungle, if you wonder why our eyes are inevitably drawn to red warning signs, red sports cars, red cocktail dresses, you have our co-evolution with plants to thank. Ever wonder why night-vision goggles show the world in shades of green? It’s largely because human eyes can detect far more shades of green than any other colour which, in our deep evolutionary past, allowed us to distinguish between toxic and tasty plants better. We are built to be botanists. That’s why I find it such a weird cultural quirk that, in modern western society, we tend to dismiss plants, and in particular gardens, as frivolous. At best, some kind of quaint, suburban hobby, at worst, merely frivolous decoration. The outdoor equivalent of drapes and scatter cushions. I’ve sat in meetings on major urban design projects when teams of fancy architects will openly refer to gardens as “developers’ parsley”: a useless garnish chucked on at the last minute. However, the reality is that study after study has consistently shown how green space can profoundly affect how we understand our surroundings, navigate the world around us, and feel about ourselves. It affects not just our mental and physical health, but how we interact with others, how we structure society. Trials demonstrate that exercise in green spaces tends to feel easier, even if subjects are burning more calories. Our levels of stress and anxiety are measurably reduced when we are surrounded by plants. Healing times in hospitals have been reported to be faster when patients are given green views. Antisocial behaviour decreases, even crime rates are statistically reduced. This research is still very much in its infancy, but it all points to some seriously transformative stuff. Of course, all of this should come as very little surprise, as we know the health of any species is dependent on its access to an ideal habitat. And whether we are doing it consciously or not, that is exactly what we are doing when we garden: engineering our surroundings to mimic the fertile, forest-edge ecosystems in which we evolved. No matter how different they appear, gardens around the world all share the same basic elements. A sheltered area, screened from view to refuge from predators, contrasted with a comparatively open space to spot prospective prey. A clean water source, ideally a fast-flowing one, which is more likely to be safe to drink, and, of course, lots of flowering species – a tip-off for the future location of tasty fruit. When we garden, not only do we make the world a more beautiful place, we also improve local biodiversity, cool overheated cities, mop up pollution and mitigate against flooding, all while improving our own health and well-being, which together have been shown to directly determine how effectively our society functions. Plants are key solutions to pretty much every major problem that faces our species today. So maybe I really do have a superpower, but I share it with all gardeners, and the only thing you need to start participating in this miracle of life is a packet of seeds. So, without further ado, here’s the Observer’s special supplement to inspire you and give you some ingenious ideas on how to get growing.