The science is in: gardening is good for you

As the weather warms and days lengthen, your attention may be turning to that forgotten patch of your backyard. This week we've asked our experts to share the science behind gardening. So grab a trowel and your green thumbs, and dig in.

"That's all very well put," says Candide, in the final line of Voltaire's novel of the same name, "but we must go and work our garden."

I studied this text at high school before I became a gardener and professional horticulturist. We were taught that Candide's gardening imperative was metaphorical not literal; a command for finding an authentic vocation, not a call to take up trowels and secateurs.

In fact, Voltaire himself really believed that active gardening was a great way to stay sane, healthy and free from stress. That was 300 years ago.

As it turns out, the science suggests he was right.

The science of therapeutic horticulture

Gardens and landscapes have long been designed as sanctuaries and retreats from the stresses of life – from great urban green spaces such as Central Park in New York to the humblest suburban backyard. But beyond the passive enjoyment of a garden or of being in nature more generally, researchers have also studied the role of actively caring for plants as a therapeutic and educational tool.

"Therapeutic horticulture" and "horticultural therapy" have become recognised treatments for stress and depression, which have served as a healing aid in settings ranging from prisons and mental health treatment facilities to schools and hospitals.

Gardening and school

Studies of school gardening programs – which usually centre on growing food – show that students who have worked on designing, creating and maintaining gardens develop more positive attitudes about health, nutrition and the consumption of vegetables.

They also score better on science achievement, have better attitudes about school, and improve their interpersonal skills and classroom behaviour.

Research on students confirms that gardening leads to higher levels of self-esteem and responsibility. Research suggests that incorporating gardening into a school setting can boost group cohesiveness.

Gardening and mental health

Tailored gardening programs have been shown to increase quality of life for people with chronic mental illnesses, including anxiety and depression.

Another study on the use of therapeutic horticulture for patients with clinical depression sought to understand why gardening programs were effective in lessening patient experience of depression. They found that structured gardening activities gave patients existential purpose. Put simply, it gave their lives meaning.

In jails and corrective programs, horticultural therapy programs have been used to give inmates positive, purposeful activities that lessen aggression and hostility during and after incarceration.

In one detailed study from a San Francisco program, involvement in therapeutic horticulture was particularly effective in improving psychosocial functioning across prison populations (although the benefits were not necessarily sustained after release.)

Gardening has been shown to help improve the lives of military veterans and homeless people. Various therapeutic horticulture programs have been used to help people with learning difficulties, asylum seekers, refugees and victims of torture.

Gardening and older people

As populations in the West age, hands-on gardening programs have been used for older people in nursing homes and related facilities.

A systematic review of 22 studies of gardening programs for older adults found that gardening was a powerful health-promoting activity across diverse populations.

One study sought to understand if patients recovering from heart attack might benefit from a horticultural therapy program. It concluded:

[Our] findings indicate that horticultural therapy improves mood state, suggesting that it may be a useful tool in reducing stress. Therefore, to the extent that stress contributes to coronary heart disease, these findings support the role of horticultural therapy as an effective component of cardiac rehabilitation.

While the literature on the positive effects of gardening, reflecting both qualitative and quantitative studies, is large, most of these studies are from overseas.

Investment in horticultural therapy programs in Australia is piecemeal. That said, there are some standout success stories such as the Stephanie Alexander Kitchen Garden Foundation and the work of nurse Steven Wells at the Royal Talbot Rehabilitation Centre and beyond.

Finally, without professionally trained horticulturists none of these programs – in Australia or internationally – can take place.

Chris Williams, Lecturer in urban horticulture, University of Melbourne

This article is republished from The Conversation under a Creative Commons license. Read the original article.