-by Lynsey Grosfield-

In Voltaire’s Candide, the source of true happiness is famously found in the sentence “il faut cultiver notre jardin” (“we must cultivate our gardens”). In many ways, Voltaire was a man ahead of his time: now, there is ample evidence to suggest his more figurative meaning should be taken literally.

 Gardening or horticultural therapy is a recognized form of intervention for several conditions: from mental health challenges like depression, to degenerative conditions like dementia, to developmental conditions like autism. Further, it can be used as a kind of physical therapy in facilitating recovery from injuries or illness: even being used with great effect for cardiac rehabilitation. It has been found to improve everything from language, memory, and cognition, to stress, balance, and coordination.

There are some basic ways in which gardening is therapeutically effective: you’re outside, surrounded by beautiful plants, and you’re physically active, with a purpose. Generally, these activities and settings are good for the mind and the body.

However, there are some unexpected actors at play in the boost that comes from gardening: these are members of the microbiome.

Mycobacterium vaccae, a harmless bacterium found in soil, was found in a 2010 study by the American Society for Microbiology to increase learning behaviour. In a subsequent 2013 study, it was found to improve symptoms of depression and anxiety, all while boosting the immune system. This bacterium is ingested when you are outdoors, toiling in the soil. It’s one of many organisms that has a poorly-understood symbiosis with animals like us.

Beyond the physical bacteria-body interactions, there are cognitive exercises that can be accomplished while gardening, in order to increase mindfulness.

Derived from Buddhist traditions, mindfulness is about learning to be entirely in the present moment. It’s not just about spiritual enlightenment: since the 1970s, mindfulness has been incorporated into Western psychology and psychiatry to great effect, improving both the mental and physical health of practitioners. 

A zen garden, for example, is not just an aesthetically beautiful place: the whole mode of cultivation and environment is meant to stimulate mindfulness meditation. The constant raking of the sand, and the maintenance of impossible perfect topiaries and bonsai plants can help the caretakers reach a state of meditative non-concentration.

While your garden doesn’t have to be a Japanese rock garden-style place of zen, it can bring the functional benefits into your life. Toil and soil on their own will improve your well-being, and going that extra cognitive step and trying to be entirely in the moment while you work will have long-term benefits for your immune system, as well as stress and anxiety levels.

While you work in the garden, in many ways, the garden works for you. It’s a kind of symbiosis.