Corbyn, leader of the Queen's loyal opposition, putters about in the garden

The single-track road dips at a stream cloaked by nettles and blackberry bushes. Across the bridge, up a gentle incline, lie more plots of land planted with fruits and vegetables and tended by the amateur gardeners who blossom across this nation.

The plot beside the stream is typical: Beds of corn and beans, trees bearing unripe apples and pears. A pile of compost under a blue tarpaulin awaits a rake. A few weeds are poking up.

The owner of this particular plot could be forgiven for taking a back seat to nature. Jeremy Corbyn – Labour parliamentarian, leader of Her Majesty’s Loyal Opposition, and, after June’s election, a serious contender to run Britain – lately has more pressing matters to attend to.

While serving in Parliament, Mr. Corbyn has found time to farm his allotment, as community gardens are known here. He mostly comes on Sundays, say fellow gardeners, and gets to work, rain or shine.

Three plots uphill, Jim Flanagan is forking his first potatoes of the season. As a retiree who comes on weekdays, he rarely sees his famous neighbor, but he admires what he’s done on his plot. “He knows what he’s doing alright. But he hasn’t got the time,” he says.

In a nation of gardeners, where TV call-in shows dispense tips by the bushel, Corbyn’s pastime is run-of-the-mill. But it fits his popular image as a modest, unmanicured politician who prefers his bicycle to a chauffeured car, a vegetarian who makes his own jam from the fruits of his labor.

During the election campaign, he presented a jar of his apple-blackberry jam to the hosts of a popular daytime show. In another interview, Corbyn was asked if he might prefer to stick to his allotment rather than occupy 10 Downing Street, the prime minister’s official residence.

“It’s possible to do both because if you grow plants and look after your garden, it gives you time to think, it gives you a connection with the natural world and makes you stronger in everything else you do,” he told Channel 4 News.

A nation of gardeners

Corbyn-as-gardener is fodder for critics who see him as a political naif not fit to run the government. One unkind comparison made is to Chauncey Gardiner, the simpleton gardener played by Peter Sellers, a British actor, whose gnomic utterances propel him towards the US presidency in the 1979 film “Being There.”

Yet in a time of populist distrust of establishment politicians, the plainspoken allotment man who pulls his own weeds may have an edge over his smoother rivals.

“He’s the perfect man, I tell you. He doesn’t bother who he’s talking to, he’s the same,” says Joe McLean, who grows flowers, fruits, and vegetables on his allotment. He pulls out his phone to show a photo taken with Corbyn in June, just 10 days after the election.

That day, Corbyn stopped by Mr. McLean’s plot to sample his cherries and Persian cucumbers (McLean was born in Iran). Corbyn also praised the trimmed flowerbeds (“That’s my son, he did all that”) and the two cracked a joke about how McLean couldn’t rely on his daughter anymore to lend a hand as she had moved to Dubai for work.

That a bountiful 12.5-acre community garden persists in a crowded corner of London is testament both to Britain’s passion for gardening and its habit of self-reliance amid wartime privations. The land was first leased to the local council to grow food during World War I; this year’s open house celebrated the 100th anniversary of East Finchley Allotments.

Allotment diggers got another boost in World War II when public and private land, including Royal Parks and the lawns outside the Tower of London, was converted into vegetable gardens as part of the Dig For Victory campaign. By 1945, the number of allotments – typically a plot of 10 poles, an Anglo-Saxon measure equal to 250 square yards – had swelled to 1.3 million.

Today, according to the National Allotment Society, Britain has around 330,000 allotment plots. Most have long waiting lists; plots are often handed down within families. At East Finchley Allotments, more than 100 applicants are pending, says Janet Francis, a member of the committee that runs the site. Turnover is low.

As a public garden, rents are modest. Standard plots rent for £85 a year (about $110), with a discount for seniors (Corbyn is 68), which covers water rates and property maintenance, says Ms. Francis.

'His private space'

Asked how long Corbyn has farmed his spot, Francis says she has no idea, but adds that it precedes her own arrival, 13 years ago.

Mr. Flanagan has tended his plot for 18 years. He grew up on a farm in County Cork, Ireland, one of nine children. Since he didn’t stand to inherit the farm, he moved to England and went into the building trade. Retirement has meant more time to plant and poke, trim and turn. “It’s a hobby for me. It gets me out of the house,” he says, leaning on his fork.

How much time Corbyn still devotes to his allotment is unclear. A weathered wooden-and-iron bench sits under an apple tree. Masking tape covers cracks in the window of a 6-by-6-ft. shed; inside tools are neatly stacked and a wheelbarrow rests on its side.

Other allotments show grander ambitions: trellis archways, paved pathways and lawns, new greenhouses. One boasts a kids’ trampoline. But many also reveal a make-do spirit, like threaded CDs hung to deter pigeons and plastic bottles atop poles so gardeners don’t poke themselves in the eyes.

At one such plot, a bearded gardener stops to talk to a reporter. He points out his corn and other vegetables, the tree fruit coming in the fall. But asked about sightings of Corbyn, his tone changes. “It’s his private space and we don’t intrude,” he says, tartly.