The Edible Gardens project, led by Dr Georgia Csortan from the University of South Australia, tracked the productivity, efficiency and potential financial savings of 34 South Australians who set up more than 100 food gardens over a year.

"We wanted to look a bit deeper into how and why people grow food in urban areas. This is the first time the economic value of sustainable home vegetable gardens has been quantified to this level of detail in Australia," Dr Csortan told AAP.

When taking into account the ongoing costs of each garden, excluding setup costs, Dr Csortan found 79 per cent of participants saved more than $250 a year on groceries.

And around 65 per cent of gardens would break even within five years, including the median setup costs of $500.

"Some people save quite a bit more if they were very productive. You're mostly looking at at least a year, at least a full season with a good summer."

The state-wide citizen science project found growers were investing just over one hour a week tending to their gardens to get a median daily return of $9.91.

Just over one in six growers produced enough food worth the minimum wage of $18.93.

"We did find smaller gardens returned greater yields per metre square and greater retail value. It's not always bigger is better."

Dr Csortan says edible home gardens are also a great way to spend time during the coronavirus pandemic, allowing gardeners to go outside and connect with nature, but also with neighbours and friends, albeit at a distance.

"Between 15 and 20 per cent of everything that people grew, they shared with others outside of their own households," she said.

Though the study is only based on South Australia gardens, Dr Csortan says the data could potentially relate to Perth, as they have similar conditions. However, other states could produce different results.

"I still don't think it would change the results too much. I think maybe people might grow food in slightly different ways in different locations."

Australian Associated Press