Food safety, availability and affordability are now global issues. Rapid urbanisation has increased demand for food in cities, where most people now live. Growing demand for food has been met by growth in industrial agriculture. Ultimately, this has led to a disconnection between urban residents and where their food comes from.

Community gardens have more recently become a popular source of urban food, and many researchers, policy-makers and activists believe that community gardens are now part of an alternative food system.

Although much of the academic literature suggests that community gardens are an effective and environmentally sound way of producing food in cities, this claim has not been substantiated.

Very little is known about how people actually garden in community gardens. The term “community garden” has been widely used to refer to any type of garden, independent of gardening practices or the philosophy informing garden development, thus putting all the gardens in the same basket.

A recent study identified sixty-five academic papers describing original research on community gardens, mostly documenting the social benefits of gardens, such as health promotion and education, community building and resilience.

But what has so far been neglected by researchers is the environmental benefits of community gardens. These include the effective management of soil nutrients, sunlight, rainfall and biological resources, factors that are essential for their long-term viability.

How community gardeners add nutrients to the soil (fertilisers vs. compost), control pests (pesticides vs. companion planting/crop rotation) and use existing resources (tap water vs. collecting rain water in tanks) are important aspects of urban ecology that warrant closer scrutiny.

This is because different gardening practises can be both environmentally beneficial (composting or locally sourcing plants and materials), or environmentally harmful (through use of synthetic chemical pesticides or limited plant diversity).

Local research in Queensland

Our study examined 50 community gardens in two of the most rapidly urbanising cities in Australia – Brisbane and the Gold Coast, South East Queensland. South East Queensland is Australia’s fastest growing metropolitan region, with its urban population expected to grow from 2.8 million in 2006, to 4.4 million people by 2031.

The main purpose of the study was to obtain a clearer picture of how the general characteristics of community gardens might shape long-term garden viability, and how garden managers' motivations affect gardening practises, with a view to informing policy on future community garden development.

Garden managers were surveyed about who runs the gardens, their motivations, the cultural background of members, their gardening philosophy, their facilities, and their gardening practices (such as soil improvement, water and energy usage).

The gardens examined were either run by schools or by a range of not-for-profit organisations. Garden managers’ primary motivations for establishing these gardens were education, community building and sustainability.

State and local government provided land and other resource for nearly all gardens, with gardens collectively occupying 57,000 square metres of land. Gardens in general, but school gardens in particular, were surprisingly culturally diverse, with members from many national backgrounds.

Almost half of the garden managers reported Permaculture as the driving gardening philosophy. Most did not use any chemicals, but seven gardens reported using synthetic fertilisers and pesticides. The ones that didn’t use chemicals used alternative strategies for nutrient soil improvement and pest control such as homemade compost, mushroom compost, blood and bone, worm castings, companion planting, planting in season and climate, and crop rotation.

Only half of these gardens, mostly the Permaculture ones, actually recognised that it was important to maintain healthy soils in order to grow healthy vegetables. Permaculture gardens used lower-impact gardening practises than non-permaculture gardens.

We found that the gardens are in fact very different, and that many are not at all environmentally sound.

Looking forward

Ultimately, the long-term viability of urban food systems is dependent not only upon social factors such as motivations and governance, but also upon environmental and ecological factors, such as the type of gardening practises used and the types of plants grown in these gardens.

Governments should be aware of these differences in gardening practises, because when it comes to community gardens, one size doesn’t fit all. Promoting community gardening as a health intervention and and providing security of tenure by allocating land for gardens is an important function of government.

But policy-makers must also become more attuned to the environmental impacts of gardening practises. They should promote Permaculture community gardens for their environmental, as well as social benefits.

Permaculture integrates landscapes, ecological processes and people, it has enormous potential to provide sustainable food. Applying these principles and techniques can enhance human well-being and promote ecological resilience. A big advantage is that Permaculture is a well-established design system that is easy to follow.

Permaculture community gardens can green cities, feed people and foster healthy ecosystems. So don’t be a couch potato, put on your gloves, grab a hat and head to your nearest Permaculture community garden for a dose of happiness, good health and delicious veggies.