Green gardens in front of houses reduce physiological and mental stress

There is growing evidence that being in natural spaces – or during gardening or listening birds singing – has a positive impact on sanity.Being in nature is also related to improvement of cognitive functions, more relaxation, coping with traumaand easing some symptoms of attention deficit disorder in children.

However, most of these studies have focused specifically on the impact of public green spaces, not private gardens. At a time when many people are staying at home due to COVID-19 restrictions, private garden spaces have been the most available green areas for those who have them. But do these little green spaces have the same benefits for our mental health?

Although the study was conducted before the current pandemic, my a recently published study found that having plants in front gardens (front yards) was associated with fewer signs of stress. Given that front gardens are becoming more common paved by developers, we wanted to look at front gardens to understand their value and impact on both the psyche, society and culture. Front gardens are also a bridge between private and public life. Because they are noticeable to neighbours and passers-by, they can also contribute to the well-being of the community.

Our experiment assessed physiological and psychological stress levels before and after adding plants to previously empty front gardens in Salford, Greater Manchester. We measured the concentration of cortisol (sometimes referred to as the ‘stress hormone’) in participants’ saliva, as well as their self-assessment of their stress. Participants ranged in age from 21 to 86, and 64% were women.

We added two pots of ornamentals – including petunias, pansies, rosemary, lavender, azaleas, clematis and either an amelanchier (snow mespilus) or a dwarf juniper tree. We chose these because they were simple to maintain and familiar to most people in the UK. We also provided compost, self-watering containers, a watering can and a trellis for the 42 residents. The research team carried out all the planting to ensure that all the gardens were similar. Participants were given advice on how to care for and water the plants and were allowed to add more plants or features. Fresh additions required as little maintenance as possible.

Less stress

Over the course of a year, we discovered that planting in previously empty front gardens resulted in a 6% drop in the number of residents perceived stress level. This scale measures the degree to which life situations are considered stressful, taking into account one’s sense of control and ability to cope with stressors. A 6% decrease is equivalent to a long-term impact eight weekly mindfulness sessions.

We also found statistically significant changes in participants’ salivary cortisol patterns. Cortisol is the body’s primary stress response hormone, which can activate our “fight or flight” response and can regulate sleep and energy levels. We need cortisol every day to be fit, and usually peak concentrations when we wake up, and decrease to their lowest levels at night. Disruptions in this pattern indicate that our bodies are stressed. We found that 24% of the residents had a fit diurnal cortisol pattern at the beginning of the study. This increased to 53% three months after adding the plants, suggesting better mental health in these participants.

The reasons for these changes can be explained by what participants told us during interviews. Residents stated that the gardens had a positive impact on their outlook on life, with robust themes developing around more positive attitudes in general, a sense of pride and greater motivation to improve the local environment. The gardens were also valued as a place to relax.

These aspects likely contribute to people’s personal resilience to stressful situations – and over time affect their physiological response to stress, as measured by cortisol levels. The diminutive addition of a few plants to the front garden was a positive change in their home environment and on the street.

All of these well-being benefits of being outdoors are believed to be based on two theories from environmental psychology: Attention Restoration Theory AND stress reduction theoryBoth psychoevolutionary theories are based on Wilson’s theory biophilia hypothesis that humans have an innate bond with the natural environment.

Attention restoration theory posits that exposure to natural environments restores our ability to focus on tasks that require effortful, focused attention. Spending time in natural environments requires less “brain power,” so to speak, because we don’t have to focus as much on specific stimuli or tasks or suppress distractions. Nature also provides opportunities for reflection. Stress reduction theory posits that natural environments elicit immediate emotional responses and fewer negative feelings than unnatural environments.

Our research results show the importance of even diminutive green spaces for stress reduction and can be critical factors in local planning, urban development and health and social care. Integrated thinking between the built environment and health sectors is necessary.

The results of this project also support the public argument for more gardens and green areas facing the street. For example, biophilic building standards, environmentally oriented urban strategiesAND initiatives for pedestrian-friendly streets could be significant ways of achieving this. Importantly for landscape architects and other professionals working with designed green spaces, there is scope for significant impact on human perception, health and well-being.

For residents who have a garden in front of their house, planting projects may require little maintenance without taking up too much space. Planting in containers may be most appealing to renters. But for those who don’t have access to an outdoor space, there’s some evidence that indoor potted plants also provide mental health benefits.