There's a lot of evidence that gardens, lawns and natural places — "green spaces," as they're called — are psychologically and physically healthy for humans. They offer stress reduction and other apparent health benefits, but there's significant discussion about why. Are humans just wired to feel and do better when they're around lots of flowers and leaves? Do they impact the way in which we think and behave in ways that give us better health? Is it some combination of both? Is being exposed to chlorophyll somehow inherently charming to us for incredibly obscure reasons?
It's National Garden Month, so it seems like a good time to explore these sorts of questions — as a motivation to get yourself near some green space if you can, whether it's your own private environment or just routing your commute through a park. If your office is cooperative enough, green indoor walls and spaces are now becoming a "thing". (The color green on its own is good for you, according to the American Psychiatric Association, but it's worth getting some living greenery in to maximize the effects.)
So what drives the feel-good factor of greenery in our lives, and why should it drive you to set up a little piece of Eden in your own backyard?
Exposure To Different Plants Fuels Our Immune System
A team of researchers at University College London set out an interesting theory for at least some of the health aspects of being around green space, and they're not down to the fitness benefits of constantly bending to pick out weeds. They explain that our physical health may well benefit from the proximity of a park to run around, but that it also provides help for our immune systems:
"it is from direct contact with animals and plants —particularly in the first weeks and months of life — that we derive the macro-organisms, micro-organisims and microbiota that live on our skin or in the gut, and these creatures have crucially co-evolved roles in the regulation of the human immune system. Without them, our susceptibility to allergies, autoimmunity and inflammatory bowel disease is much increased."
It's an interesting perspective that also, as the researchers point out, can have impacts on mood, because "the same organisms and processes that help our immune system combat inflammations also modulate brain development, cognition and mood." With this in mind, it's interesting to bring in a 2007 study that found that the more biodiverse a green space was, the more psychological benefit people gained from it; essentially, the more species of plant, the happier people were. Biodiversity in gardens and parks might, if this theory holds true, help raise our mood by enriching our immune systems. It's a good enough reason to get several varieties of flower for your tiny outdoor patch.
Green Spaces Provide A Mini Escape From Our Lives
When it comes to the psychological side of green spaces and how we interact with them, there's one thing that pops up a lot: the idea of "restorative" time. This theory is based around the idea that we get restorative value from spending time in green places like gardens, for a few different reasons. The Lancet explained in 2008 that
"This restorative value seems to stem from mutually reinforcing aspects of experiences of nature: distance from everyday demands, and possibilities for aesthetic appreciation and activity driven by interest."
In other words, we get benefits from time in natural spaces because they give us space from normal life and make us take time to appreciate beauty. The idea of green spaces being a "buffer" that helps us cope with stressful life events was borne out by a 2010 study that found that proximity to green space in a 3km radius was directly related to how well people thought they could respond to stress and worry. The restorative value of nature, according to Scientific American, might be because it takes our attention benignly and chills us out, rather than requiring intense focus and thought.
But there are other aspects of greenery, particularly public gardens, that could be helping our psychological health. One, suggested in 2008, was that spending a lot of time in public green places might foster a sense of community, because even if you don't talk to the woman who walks her terrier there every day, you still feel bonded.
Another study, however, went into detail about how we see green places, and gives us a brilliant insight into why we view them as psychologically valuable: it asked nearly 1000 Swedes to answer a questionnaire about the "sensory dimensions" of environments and how they viewed stress. Nature and ideas of refuge came out as strongly correlated to stressful thoughts, indicating that Swedes at least turn to green spaces when they're feeling upset or want to feel protected. According to that study, we don't necessarily want our gardens and green spaces to be filled with other humans. "A combination of Refuge, Nature and Rich in Species, and a low or no presence of Social, could be interpreted as the most restorative environment for stressed individuals," the researchers noted. Hence private gardens and their reputations as calming places.
Maybe We've Just Evolved To Like Green Stuff
This is a controversial one. Professor Graham Rook, who heads the University College London research group, explains that some theorists believe that we like being around greenery because we're just evolved to do so by our many centuries living in natural environments and finding them comfortable:
"We evolved as hunter-gatherers in open spaces, usually following rivers, coast lines and the shores of lakes. Therefore contemplation of such environments might fulfill a psychological need."
However, not everybody is so convinced that our evolutionary "attachment" to nature is what's really helping us out psychologically. Rook himself is more a fan of the biodiversity-immune system theory, while others are skeptical on the basis of cultural norms. It wasn't until the 19th century, for instance, that Europeans viewed wilderness and the untamed natural world as anything other than brutish and terrifying matter that needed to be "shaped" to become beautiful. (Blame the Romantics for shifting that and going wandering around looking looking for hosts of golden daffodils.) Our ability to look at "natural" green spaces may still be informed by our cultural beliefs about taming nature and the value of wild places.
Though they're all intriguing, these theories don't have to provide one single explanation for why it's a good idea to get yourself a) a garden or b) some green space in your life. They can combine to point out the many values of getting yourself deeply involved in the local garden center, or at the very least seeking out the closest park and going for a "restorative" stroll on the regular.