Spending a short time on an allotment once a week can improve mood and help people maintain a healthy weight, according to a study.
Even just half an hour at the allotment has physical and mental health benefits, a team of researchers from the universities of Westminster and Essex found.
They said local councils should take heed of the findings and provide allotment space, particularly for people with small gardens or those living in towns and cities.
The research, published in the Journal of Public Health, involved 269 people who either had an allotment or did not garden.
They were from a variety of backgrounds, with some high earners, others on low incomes and a variety of health or disability problems.
The results showed that just one session of allotment gardening could result in significant improvements in both self-esteem and mood.
Working on an allotment reduced feelings of tension, depression, anger and confusion, the researchers found.
People were asked about their moods and feelings via a questionnaire and also filled in details of their body mass index (BMI).
Allotment dwellers had fewer weight problems, the study found. Some 47% of gardeners were overweight or obese, rising to 68% of non-gardeners.
Co-author, Dr Carly Wood, from the University of Essex, said the overall length of time spent on an allotment did not alter the findings.
People who had been gardening for a short time also experienced similar benefits as those who had had their allotments for several years.
She said: "Participants who attend an allotment for a short period just once per week can experience a similar magnitude of improvements in self-esteem and mood as participants who attend more regularly for longer periods of time."
The researchers said in their paper that more should be done to encourage allotment gardening.
"With an increasing number of people residing in urban areas, a decline in the number of homes with gardens, and the increased risk for mental ill health associated with urban living, these findings are particularly important and suggest that allotment gardening might play an important role in promoting mental wellbeing in people residing in urban areas.
"However, the lengthy waiting lists for allotment plots throughout the UK, and the reduction in the availability of green spaces in urban areas are limiting the ability of people to have access to nature close to their homes.
"Community allotment plots might provide a feasible solution to this problem as they allow all people to access an allotment and to take part in green exercise; in addition to promoting social interaction, community inclusion and opportunities for healthy eating; all of which promote wellbeing.
"Local public authorities should therefore seek to provide community allotment plots in order to improve the health and wellbeing of their residents."
Professor John Ashton, president of the UK Faculty of Public Health, said: "We cannot have good physical health without also looking after our mental wellbeing. We would welcome more community allotments and opportunities for people to have access to safe, green spaces.
"Because there are long waiting lists for allotments, we need a strategy that considers how we could make better use of neglected land that marks the transition from towns to cities."