Plant life

The positive effect of green spaces on our mental health is now being backed by science 

In 2012, I quit my office-based job to become a freelance journalist with the hope of living a more balanced life. Long hours and commuting had left me feeling like time for a change.  

I set up a desk in my spare room overlooking the garden, which was a neglected set of flowerbeds arranged around a brick courtyard. As the months passed, I found myself spending more time outdoors, tidying the garden or going for a walk around the local park in the afternoon sunshine. I began to notice the wildlife and became familiar with the annual cycle of plant life. I found that after working in the garden or walking outdoors, I felt calmer and more present, my productivity increased and my mood improved. Friends and family even remarked on the shift in me. 

And science is now backing the benefits of green spaces on our mental health. 'I was astounded by the variety and range of the evidence,’ says author Lucy Jones, who unpacks some of these scientific studies in her book, Losing Eden, published this year to critical acclaim. 

She discovered that time spent in nature is linked to lower stress, restored attention, a balanced nervous system, increased levels of cancer-fighting 'natural killer cells', the activation of neural pathways associated with calm, and decreased levels of anxiety and depression. 

In Losing Eden she also details how simple pleasures, such as listening to birdsong or taking a walk in the woods, can reduce activity in areas of the brain associated with negative rumination, sadness, and decision-making. As a result, cortisol levels – the hormone associated with stress – have been shown to fall following these activities.

Astonishingly, one study showed that even just looking at fractal shapes – self-repeating patterns that vary in scale – can make us feel calmer and less irritable. These fractal shapes, which can be found everywhere in nature – think ferns, seashells, snowflakes and ocean waves – provoke high alpha waves in the brain’s frontal lobes and high beta waves in the parietal area, promoting a relaxed but focused state of mind. The evidence indicates that any view on to nature, even if it's via a screen or picture, can have measurable therapeutic benefits. 

Author Sue Stuart-Smith picks up the argument in her bestselling book The Well Gardened Mind: Rediscovering Nature in the Modern World, also published this year. She suggests that modern life is eroding this beneficial connection to the natural world. 'Natural spaces are particularly rich in sensory pleasures,' she writes.

'These days we are increasingly surrounded by functional places lacking in character and individuality, like supermarkets and shopping malls. As a result, the notion of place in contemporary life has increasingly been reduced to a backdrop, and the interaction, if there is any, tends to be of a transient nature rather than a living relationship that might be sustaining.' 

Perhaps, then, it’s no surprise that in the UK, 11.7 million working days are lost annually due to stress, depression or anxiety. Other countries, such as Japan and South Korea, have been much quicker to harness the power of the natural world to combat the anxiety caused by modern life. 

In Losing Eden, Jones details how Japanese doctors prescribe mindful walks in the woods for patients who are suffering from anxiety induced by hectic urban life. Called shinrin-yoku, which translates as 'forest bathing', the practice was first proposed by the Japanese Forestry agency in the 1980s but has roots in ancient Shinto and Buddhist ideals of harmonic balance with nature. In South Korea, the government recently invested $14million in a National Centre for Forest Therapy where it is training 500 forest-therapy instructors. 

In the UK, we are slowly catching up. As scientific evidence has been building, so too has awareness of the importance of green spaces and plants.  

Andy Davidson is head designer and area manager of Lease a Leaf, which supplies companies across the UK, including TOG, with plants for office spaces. 'There has been a massive shift in the last five years in the amount of greenery going into office spaces, especially in London and other cities,' says Davidson, whose company is currently leasing over 50,000 plants around the UK. 'The main thing we get asked about when it comes to choosing plants for an office space is: which types of plants will be best at cleaning the air?' 

To answer this question, Davidson refers to a clean air study conducted by NASA in 1989 that suggests that we should have at least one plant per 100 square feet of home or office space. NASA’s researchers found that plants with large broad leaves, such as Devil's Ivy or Monstera, are the best natural air purifiers. The Peace Lily and Florist's Chrysanthemum in particular are effective at removing benzene, formaldehyde, and trichloroethylene, xylene, and ammonia from the air – all chemicals that have been linked to health effects like headaches and eye irritation. 

For Lucy Jones, office workers should also be encouraged to take full lunch breaks where they can spend time in natural environments. She also suggests employers encourage walking meetings in nearby green spaces, and protect the trees, parks, gardens and waterways that make up the wider environment around the workplace. 

'Giving employees time and space, and acknowledging and connecting and engaging with the rest of nature, is a vital element of good mental and physical health,' she says. 'It is more crucial than ever.' 

Andy Davidson of Lease a Leaf Limited shares his top plant recommendations for happier and healthier work environments: 

Monstera (Swiss cheese plant): Lovely large dark green foliage. Large leaf pads are good for air purification and the natural wild growth habit of the leaves and air roots makes for a relaxed, luscious visual to increase the mental relaxation.  

Robusta (Rubber plant): Again this plant has nice large leaves. It’s very dark in colour, which allows for good contrasting with other green foliage. It’s great for air purification and its rounded foliage will please any feng shui enthusiasts. 

Kentia (Paradise palm): Good for dark areas with low natural light, the Paradise palm’s mass of green foliage is not only soothing for the mind but also perfect for cleansing the air.  

Philodendron Scandens: This trailing plant can thrive in areas with poor natural light levels and requires only a shallow root space. 

Strelitzia Nicolai: People mistake these for banana plants but they are actually the non-flowering variety of the Bird of Paradise plant. The lovely, large torn leaves give them a jungle-esque look but were actually evolved to help them survive in their natural habitat where the strong winds would uproot the plants. Although some people presume the sloping tears are due to bad health, the jagged edges actually serve as natural gears to let the wind through.  

Zamioculcas (Zamia/Zz plant): These plants boast very glossy foliage and a nice dark green colour that contrasts well against other plants. They are good air cleaners, very hardy and good at tolerating lower light levels.  

Aspidistra: These are also known as Cast Iron plants because they're almost impossible to kill. They have beautiful tall foliage for the size of their root balls. Aspidistras make for a very hardy but relaxed visual. 

Ali Morris is a writer, editor and consultant who has worked with Wallpaper*,  Dezeen  and Elle Decoration, among others