Just one woman at Chelsea, peering through a thicket of foxgloves with a wry smile on her face, has clocked the quiet man in the brown shirt, owner of the most famously satirical eye in British photography. Martin Parr, she has realised, has invaded one of the most prestigious flower shows in the world.

“It does happen that somebody recognises me, but not often – and certainly not at Chelsea,” Parr says. “It happens if I go to London openings, but these people on the whole don’t go to exhibitions, they just like plants, they only go to gardens.

“I’m always interested in people and Chelsea is heaving with a certain type: rock-solid middle England, middle-aged, middle-class, grey hair, grey pound – still a very important part of the constituency. It’s as white as it gets: I think the only ethnic minority people I met were stewarding or working in the shops.”

I do love Chelsea. I love anywhere where there are people Martin Parr

Anyone who does recognise Parr might worry they are about to be gently mocked in searing colour, like his scorched ice-cream eaters on pebbly beaches, or his silent couples perched glumly at cafe tables.

He can barely tell a dandelion from an orchid, but he loves Chelsea, where every hat bears more flowers than any show garden, every recklessly patterned shirt is stretched over a post-prandial stomach.

“Oh, I do love Chelsea,” he says. “I love anywhere where there are people. That’s my only dread, that there won’t be enough people, and you don’t have to worry about that at Chelsea. The only problem is that there are just so many of them, you have to fight your way through the crowds.”

Parr has been accused in the past of artificially tweaking the colours in his images: “Another urban myth about me, not true.” But that’s not a problem at Chelsea – it bursts with colour.

Having captured a man in crimson trousers intently studying some Wedgwood china that matches his floral shirt, Parr positions himself by a violently pink rose.

“I thought it would be fun to do a sequence of people smelling the same rose, and I knew this was the one. It had the maximum smell in appearance and the minimum in results – that accounts for the expression of disappointment on so many of the faces.”

Many people have given up even pretending to enjoy themselves. He snaps one bench entirely occupied by weary figures who have been left minding the shopping.

Few men feature in his Chelsea images. Parr spends the next day at the cricket, realising where all the men have gone. “These are two perfectly matched events – exactly the same types, but the men are at Lords and the women are at Chelsea. Two sides of the same coin.”

He is going back to Chelsea for the last day, when the temporary gardens are dismantled and sold. “Mobs of people staggering out trying to carry plants bigger than themselves – that’s what I’m hoping to see. Lovely.”