What could possibly be more innocuous than a garden? The primary place for “pottering about”, the garden is the ultimate middle-class space to unwind, stealthily one-up the neighbours, and worry about unimportant minutiae such as when to prune the apple tree or how to attack an unsightly yellow patch of grass.

Among gardeners happily trampling this stereotype, and a handful of others to boot, is Juliet Sargeant. The first black female designer to create a garden for the Chelsea Flower Show, she is using her exhibit in the Fresh category to raise awareness of modern slavery. At its centre is an oak representing the the “Wilberforce Oak”, the tree in Kent under which in 1787 William Pitt challenged his friend William Wilberforce to first bring abolition before parliament.

By bringing an issue such as slavery – certainly not typical dinnertime conversation – to the flower show, Sargeant not only highlights an important issue but draws attention to how the show is a symbol of the establishment. It is, after all, an event held in an exclusive area of one of the most expensive cities in the world: where space is at a premium and the housing crisis shows little sign of slowing.

If gardens are considered blank canvases of land on which to express the identity and tastes of a household or a city, they become undeniably political. Most obviously, gardens are bound to environmental issues, but also and more subtly to ideas of ownership, property and inequality.

The domestic garden is your own small green patch of earth there’s deep micro-politics in how you treat that <p>Professor George McKay</p>

“The domestic garden is your own small green patch of earth there’s deep micro-politics in how you treat that,” says George McKay, professor of media studies at the University of East Anglia and the author of Radical Gardening: Politics, Idealism and Rebellion in the Garden.

The seemingly unimportant choice between keeping an immaculate lawn or a messy vegetable patch prompts a gardener to consider whether they should use chemicals or stay organic. The personal is political, and a gardener’s choices are comparable to opting for a vegan or a meat-eating lifestyle.

Professor Bryony Hoskins of the University of Roehampton’s department of social sciences, believes that political activities have become more individualised, and gardening is no exception. “A garden is a space where the personal and everyday merges into the public sphere, somewhere in between the privacy of your home and the street,” she says.

Perhaps gardens aren’t so personal after all. In certain neighbourhoods, an unkempt plot or a misplaced gnome can become a prickly issue, as anything damaging the pristine image of a street can affect all-important house prices.

Sara Jane Trebar is campaigning to save her local allotment in Watford, where ‘neighbours of all backgrounds, cultures and religions work side by side in peace’

Sara Jane Trebar is campaigning to save her local allotment in Watford, where ‘neighbours of all backgrounds, cultures and religions work side by side in peace’ (Sara Jane Trebar)

In fact, tending to the land has always been fraught with meaning. The Diggers, Protestant radicals widely regarded as proto-anarchists, believed the poor should own land. The 20th century, meanwhile, ushered in the rise of “guerrilla gardening”, where groups transform public spaces by night without seeking permission. This may seem like a friendly act of community service, but it has sometimes ended in violence. At Berkeley university in California in 1969, students turned a disused car park into a “people’s park”. Then-California governor Ronald Regan reacted by closing the park. Police shot a man dead in the resulting protests.

“The guerrilla gardening movement has seen gardening become a people-powered and more urban phenomenon, drawing attention to urban spaces. Some artists like Paul Harfleet have used guerrilla gardening as an explicitly political statement, with his Pansy Project confronting homophobia and hate crime,” says Paul Green is the co-founder of the Avant Gardener artists collective.

But green spaces are not merely hotbeds of political revolt; community gardens can also aid social cohesion. Green established Avant Gardening with artist Polly Brannan to encourage engagement between artists and communities.

“While there may be a historical perception of gardens being the preserves of stately homes and the elite, the likes of William Morris believed that natural spaces and gardens were enriching and they were central to their radical utopianism,” he says.

The London Community Flower Show taking place in Southwark Park in south-east London next autumn is the latest example of an inferred anti-Chelsea attempts to democratise gardening.

“Next year London's gardeners can look forward to a flower show for them, by them,” says Geoff Juden, the chairman of the East London Garden Society and organiser of the show. The event promises to give enthusiasts a chance to showcase their skills without a show garden in sight, and will be accompanied by a market celebrating the capital’s food.

“The best bit? Money from ticket sales will go directly back to London's gardeners in the form of grants to improve their skills and produce,” says Juden.

Those without the stomach for guerrilla gardening or who prefer a more personal approach to the practice but don’t have a plot to call their own can retreat to their local allotment. But even the humble allotment is a political statement. McKay describes them as “profoundly anti-capitalist” spaces.

“Think about it: the rents charged by your council for a plot are really very small, and often bear little relation to the actual land value as, say, developers might see it. That’s a wonderfully willful rejection of commercial property value right there.”

The Chelsea Flower Show 2016 - In pictures Show all 8 1 /8 The Chelsea Flower Show 2016 - In pictures The Chelsea Flower Show 2016 - In pictures A Chelsea Pensioner holds a rose as he stands in the 5000 Poppies Garden ADRIAN DENNIS/AFP/Getty Images The Chelsea Flower Show 2016 - In pictures Britain's Queen Elizabeth II is pictured through a gap in a floral exhibit by the New Covent Garden Flower Market, which features an image of the Queen, during a visit to the 2016 Chelsea Flower Show REUTERS/Adrian Dennis/Pool The Chelsea Flower Show 2016 - In pictures Prince Andrew, Duke of York with Juiet Sergeant in the Modern Slavery Garden attends the Chelsea Flower Show press day at Royal Hospital Chelsea Heathcliff O'Malley - WP Pool/Getty Images The Chelsea Flower Show 2016 - In pictures A band prepares to play at RHS Chelsea Flower Show Chris Jackson/Getty Images The Chelsea Flower Show 2016 - In pictures A couple read a brochure and eat ice cream at the Chelsea Flower Show. The prestigious flower show has been held annually since 1913 in the Royal Hospital Chelsea grounds. Jack Taylor/Getty Images The Chelsea Flower Show 2016 - In pictures A model poses at the Chelsea Flower Show in London Eamonn M. McCormack/Getty Images The Chelsea Flower Show 2016 - In pictures A man wearing a flower-themed suit walks through the tulips on display on the Blooms Bulbs exhibit ADRIAN DENNIS/AFP/Getty Images The Chelsea Flower Show 2016 - In pictures An assortment of cacti on display at the Chelsea Flower Show Jack Taylor/Getty Images

A skilled allotment-keeper able to grow a glut of vegetables cannot profit from their spoils, he adds, and, often compelled by law, give away what they have grown. “So, again, the cosy hotch-potch bee-busy DIY dirty green space of the allotment is actually a hotbed of anti-capitalist gift economy.”

Rising land prices have seen allotment holders fighting to save their plots from the clutches of developers. Watford resident Sara Jane Trebar is campaigning to save the Farm Terrace allotment in the Hertforshire town against council plans to build over the area. “To me allotments symbolise peace, communities and freedom. There are few places left in today’s society where neighbours from all different backgrounds, cultures and religion come together in peace to work side by side,” says Trebar.

“The political gardener in me enjoys being self-sufficient. There is no greater feeling than looking at a plate of food and knowing that you grew it all.”

Let’s not forget, however, that as what land represents is malleable, the right wing are as eager as the left to use gardens as political symbols.

“Nationalism and planting have awkward complex roots too. The Nazis fetishised the land, many were committed organicists and biodynamicists in their planting,” says McKay. “Even a few years ago the BNP were calling on gardeners to plant 'good British' varieties of heritage fruit trees, to protect British tradition in the garden.”

There is no greater feeling than looking at a plate of food and knowing that you grew it all.” <p>Campaigner Sara-Jane Trebar</p>

Plants themselves are also loaded with meaning, from red poppies to remember the war dead to white poppies worn as a celebration of peace, and from white lillies at funerals to floral symbolism in Pre-Raphaelite paintings.

These are all things that can be pondered at leisure, as one thing the slow, cyclical nature of gardening offers is plenty of time to think. Indeed, not only are gardens loaded with meaning, but the very act of gardening can feel profound in its relationship with living things and with time itself.

“Plant some biennial flowers and you are kind of investing in the future, because you are not going to see a display for one or two seasons,” McCay muses. “Put a couple of pear trees in your green patch and you are really looking 20 to 30 years ahead. These are acts of faith in a future world, aren’t they?”