We have often been told that doing some gardening can benefit us physically.

Now scientists believe getting outdoors to rake the leaves and pull up weeds could help our mental wellbeing as well.

Many of us work in grey office buildings, spending hours stuck in traffic and constantly staring at computer and TV screens.

And environment expert Dr Ross Cameron suggests our busy modern lifestyles are sapping our spirits.


He refers to this as "nature deficit disorder". The Sheffield University lecturer, delivering the Royal Horticultural Society's annual John MacLeod Lecture on Thursday, said: 'We are less observant of the natural world around us, we are actually physically doing less, people are getting more obese and physically less active.

"That's partially because we are not accessing green spaces and getting out and running and playing the way that previous generations did."

For those who cannot access the great outdoors, spending time in the garden can provide the answer, he said. "Green spaces don't need to be the wilderness that provide benefits, they can be at your back door.

"They can be intimate close spaces that you engage with and we can make them occur more often and we can make them better quality for our own wellbeing.

"The physical activity helps you relax, there's implications for mental health so you're more likely to be in a relaxed state. That's one of the great things about green spaces - they are stress-busting environments. Just having a little bit of greenery around makes us more relaxed."

Dr Cameron, who specialises in "the integration of ecology in urban landscapes", added: 'We are now largely sedentary, societal change is driving this.

"The youngest generation is the most critical - they are engaging with a virtual world rather than a natural world, sitting in front of their mobile phones all day.

"In the past they would bat a ball against a wall or go and play in the woods - that is now very rare.

"Children in their early teenage years are estimated to spend an average of seven hours and 30 minutes a day in front of a computer, television or mobile phone screen."

Humans are hard-wired to respond to nature - with previous research suggesting just half an hour in the garden has long-term benefits for body and mind.

And another study found that sounds of nature, such as wind whistling through the trees and a running stream, reduce levels of the stress hormone cortisol and lower blood pressure.

Growing evidence suggests regular gardening can also reduce the risk of heart disease, cancer and obesity. It also improves balance, helping to prevent falls in older people, a cause of major costs to the health service.

Gardening also can help dementia patients, with one trial showing that six months of gardening at home resulted in a slow-down of cognitive decline over the next 18 months.

The Royal Horticultural Society calculates that half an hour of digging burns 150 calories, raking a lawn burns 120 and pushing a lawn mower for 30 minutes burns 165.

While running may use up about 240 for a half an hour jog, doctors are increasingly encouraging people to take up lighter activities they can more easily weave into their daily routine.

A major report by the King's Fund health think tank, published in May, suggested gardening should even be prescribed on the NHS.