There is a golden hour on a summer evening in Greenwich Park when the light goes soft over the river, the city glitters in the distance, and a hundred lanyard-wearing office workers are sprawled across the grass in various states of Pimm’s-induced contentment. It is, for about twenty minutes, genuinely lovely. Then everyone drifts off towards the DLR, and what they leave behind on that beautiful royal lawn becomes my problem. If the corporate Christmas party is winter’s indoor carnage – all mulled wine, candle wax and a function-room deposit on the line – then the summer social is its sunlit opposite: outdoors, sprawling, and scattered across some of the most cherished green space in London. I clean up after both, just a short hop from my place in Catford, and swapping a hotel ballroom for Blackheath in July changes absolutely everything about the job. Here is how.

Why a Summer Social Is the Mirror Image of the Christmas Do

Everything that makes a Christmas clean-up hard, a summer one makes hard in reverse. The festive party happens in a sealed room, which is a curse in some ways – everything soaks into one carpet – but a quiet blessing in others, because the mess has nowhere to go. A summer social has no walls at all. Spread a few hundred people across an open park and the rubbish goes wandering with them: cans rolling down the hill, paper plates skating off on the breeze, sandwich crusts flung optimistically towards a bin and landing nowhere near it. Where the Christmas do concentrates the damage, the summer social distributes it, and a wide, breezy distribution is a great deal harder to chase down than a single stained rug.

The cast of villains changes with the season, too. Out goes the mulled wine and in comes warm rosé and spilled Pimm’s, fruit salad and all – the last of the summer wine, quite literally, soaking into the turf. Candle wax gives way to barbecue grease. The frostbitten smokers huddled by a fire exit in December become sunburnt colleagues dozing under a tree in July, and the dropped canapé becomes a dropped sausage, swiftly claimed by an opportunistic crow. It is the same essential event – people, drink and food in quantity – simply photographed in negative.

Open Ground Changes Everything

The single biggest shift is the ground itself. Indoors you work a defined space with a clear edge, and you know precisely when you have finished because you can see all four walls. On open parkland there is no such comfort. Litter migrates downwind for surprising distances, tucks itself deep into long grass and tree roots, and tumbles into flower beds and ha-has where it is absolute murder to retrieve. You cannot simply run a hoover over a hillside. The job becomes a methodical sweep on foot, line abreast, eyes down, across an area many times the size of any ballroom, and you only know it is done when you have walked every inch of it twice.

The Disposable Barbecue Problem (and Other Summer Specials)

If the Christmas party has its signature menace in candle wax, the summer social has the disposable barbecue, and I have come to regard the wretched things with a very particular loathing. People buy them for a few quid, light them on the grass, cook their burgers, and then – this is the bit that makes me wince – simply walk away, leaving a foil tray of coals that stays dangerously hot for hours. On a dry July lawn this is not merely litter; it is a scorch mark burned into the turf, a branded ring of dead grass that can take a whole season to recover, and on tinder-dry common land it is a genuine fire risk that no responsible event should ever leave behind it.

Then there is everything else the season throws up. Barbecue grease congeals on paper plates and soaks into the ground. Food waste, which would sit harmlessly cold in December, turns within hours in the heat and draws wasps in furious clouds. Half-finished cans of warm lager attract every insect in the postcode. There are sun cream bottles, deflated balloons, snapped tent pegs from a collapsed gazebo, and the inevitable single flip-flop whose partner has vanished entirely into legend. Each is minor on its own; together, baking gently in the sun, they add up to a sticky, smelly, fast-deteriorating mess that will not wait politely until morning the way a frozen one will.

Scorch Marks and Hot Coals

The hot coals deserve a paragraph all to themselves, because they are the one part of a summer clean that is actively dangerous rather than merely grim. A disposable barbecue can hold enough heat to burn a hand or start a grass fire long after the last guest has wandered off convinced it had “gone out”. We douse them properly, check the ground beneath for anything still smouldering, and never, ever bag hot coals in with general rubbish, a lesson the whole industry has learned the hard way. On protected heathland during a dry spell, one carelessly abandoned barbecue is all it takes to do real and lasting harm.

Cleaning on Royal and Protected Ground

Here is something that quietly raises the stakes in this corner of London: you are not tidying up any old field. Greenwich Park is a Royal Park, part of the UNESCO-listed Maritime Greenwich, and it sits at the very centre of the riverside Greenwich the whole world recognises – the Observatory, the Meridian where time itself officially begins, and the Old Royal Naval College so beloved of film crews that you have almost certainly watched a period drama swoon over its colonnades without realising where you were looking. Blackheath, just over the brow of the hill, is protected common land with its own deep and storied history. These are not spaces you can leave looking second-best, and the bodies that manage them quite rightly hold events to a high standard.

Which means the clean-up is held to one as well. Ground protection genuinely matters; you cannot drag heavy bins across heritage turf or churn it up with a vehicle. Litter standards are exacting, because a stray bottle on a royal lawn is a far worse look than one in a hired hall nobody will remember. And glass becomes a serious responsibility on ground where children play and people walk barefoot – a single smashed prosecco bottle, scattered invisibly through summer grass, is a hazard that can linger for years if it is not found and cleared with real care.

Sharing the Space with Deer, Dogs and Joggers

You are also, crucially, never alone out there. Greenwich Park still keeps its herd of deer, and litter is no laughing matter to a deer; swallowed plastic and foil can kill an animal that picks it up while grazing. By early morning the parks fill with dog-walkers, joggers and parents with buggies, every one of whom expects the green space to be exactly as pristine as they left it the evening before. A summer clean is therefore a race not against a function-room deadline but against the public themselves: get it wrong, and your leftover mess is on display to half of south-east London by nine in the morning, with the local wildlife having got to it first.

Racing the Heat Instead of the Cold

Cast your mind back to the Christmas piece and you will recall the enemy there was the clock – that brutal overnight turnaround before the room was needed again at eight sharp. In summer, the enemy is the heat, and it imposes a deadline all of its own, just a more biological one. Everything organic left on that grass begins to turn the moment the sun gets on it. Food that would happily keep for hours in a cold December hall is rancid by morning in July, the wasps have moved in, and what was a manageable tidy-up at dusk curdles into a far grimmer job by dawn. The smart move is to clear the bulk of it while the event is still winding down, rather than leaving it to ripen overnight in the warmth.

The work itself is harder in the heat, too, in a way people rarely stop to appreciate. Cold-weather cleaning is miserable, but at least the cold preserves things; hot-weather cleaning means graft in full sun, constant hydration, and a real effort to stop your crew wilting halfway up a hillside. Where the December team battled numb fingers and frozen bin bags, the July team battles sunstroke and the smell. Same job, precisely opposite hardship, which is rather the theme of the whole summer-versus-winter business.

Done Before the First Dog-Walker

For all those reasons, the goal is to finish early and finish completely, before the heat and the public both arrive in force. There is a particular satisfaction, just as there is on a clear winter morning, in standing on a Greenwich hillside at half past seven, watching the first joggers pound up towards the Observatory across grass that only twelve hours earlier held a few hundred merry colleagues and their entire buffet – and seeing not a single trace of any of it. The Christmas do and the summer social could hardly be less alike: one indoors and frozen, one outdoors and baking, one a battle for a deposit and one a duty to a royal park. But the measure of a job done well is identical in both. When nobody can tell you were ever there, you know you have done it right.