What began with small talk between Prince Charles and the sustainable fashion pioneers Vin + Omi over a Victoria sponge will next month result in dresses made out of nettles from the prince’s Highgrove estate hitting the London fashion week catwalk.

The prince met representatives of the British design industry for tea last year as part of the Positive Fashion initiative, which promotes sustainability, best social and environmental practice, equality and local production.

In an effort to deflect conversation away from the subject of the imminent wedding of his son Harry, he seized on a mention of the use of nettles in clothing. “I’ve got lots of those at Highgrove,” said the Prince when he met the design duo Vin + Omi, who were branching out from experimentation with a fabric made from cow parsley. “We didn’t think much about it at the time,” says Vin, who, like his partner Omi, goes by a single name.

Facebook Twitter Pinterest Vin + Omi with their clothing line, made from recycled plastic, in March 2018. Photograph: Katherine Anne Rose/The Observer

An invitation to Highgrove arrived soon afterwards. “It was quite surreal,” says Omi. “We are not establishment at all. Our look is 1980s Camden punk. I mean, it’s not like we are Gucci or someone like that.” After meeting with the head gardener at the Gloucestershire royal estate, where there is a strong emphasis on recycling, the designers recruited a team of students from Oxford Brookes University to help harvest 3,000 nettle plants.

“The Highgrove team are really relaxed, but it was hard work in hot weather,” says Vin. “You can’t wear shorts or short sleeves, or you’d get stung to death.”

When the 10 or so pieces of nettle clothing make it on to the catwalk of the Savoy, on the last day of London Fashion Week, what the audience will see is a “fabric you might think was a type of alpaca, or maybe a very fine fleece”, says Omi. “It’s a wispy, airy sort of texture – you wouldn’t recognise it as nettle at all. That’s the whole point, to make a contemporary garment out of a waste material.”

Nettle fibres have been woven into fabric since Roman times, but the designers worked on a new technique whereby the fibrous strings from each stalk were developed into a fluffy, wool-type fibre and processed with environmentally friendly saltwater bleach to take out the green. Jewellery worn with the nettle dresses has also been made from Highgrove plant waste.

Facebook Twitter Pinterest The Prince Of Wales checks out sustainable clothing at the Yoox Net-a-Porter offices, in London, on May 16 2018. Photograph: WPA Pool/Getty Images

“Nettles are perceived to have no value,” says Omi. “Hopefully that challenges the way we think about fashion. Nettles are everywhere, they are a weed, they are an abundant natural resource in this country. We want to start people thinking about how fashion can work with what the environment has on offer, rather than forcing itself on the environment in harmful ways.”

Prince Charles is “very appreciative” of the project, say the designers, and has sent letters of encouragement. “Every so often the postman turns up with a registered post letter, bearing the royal seal.” The Victoria & Albert Museum, in London, has already asked for a piece for its archives.

Vin, who is British, began working with Omi, who was born in Singapore and worked for Christian Dior under John Galliano, in 2004. From the outset, sustainability has been their fundamental guiding principle; they describe themselves as an ideology as well as a fashion label.

“Fifteen years ago, people called us hippies,” recalls Vin. “The fashion industry still has a huge problem [with sustainability], but at least that is acknowledged now.” He does not believe, however, that change is happening fast enough. He points to many aspects of the fashion system that are wasteful. “For instance, the promoting of a new designer who has short-lived success and then suddenly goes bust – there is so much waste in that.”

The pair, who have dressed Michelle Obama, Debbie Harry and Kate Moss, have partnered with the Savoy as advisers on sustainability. From next spring, the hotel’s doormen will wear a Vin + Omi uniform which will be made from fabric created out of the hotel’s own plastic waste.