Prince William’s Eco-Sneaker Confession Turns Heads in Cape Town: 'He Said He's Got a Pair!'

The Prince of Wales was at the Kirstenbosch National Botanical Garden in Cape Town, South Africa, on Nov. 6 to meet his Earthshot Prize finalists

• Prince William revealed he owns a pair of eco-friendly sneakers during a visit to Kirstenbosch National Botanical Garden in Cape Town, South Africa, on Nov. 6
• “He said he’s got a pair!” Mary Allen of Natural Fiber Welding told PEOPLE of the Purified shoes
• The Prince of Wales is in South Africa promoting his Earthshot Prize Awards

Prince William revealed another eco-friendly fashion choice as he took a stroll through the spectacular Kirstenbosch National Botanical Garden in South Africa on Nov. 6.

The Prince of Wales, 42, shared that he has a pair of sneakers that are made with materials from one of his Earthshot Prize finalists as he walked through the garden, which is nestled in the foothills of Table Mountain, Cape Town.

William was talking to Mary Allen from one of the shortlisted companies, Natural Fiber Welding, which makes plastic-free materials for use in shoes, bags and textiles. The prince met Allen and representatives from 14 other finalists who form the Earthshot Prize cohort this year.

“He said he’s got a pair!” Allen tells PEOPLE of the Purified sneakers that use the plant-based materials created by the Illinois-based company.

The prince’s eco-fashion choices have been capturing attention during his visit to South Africa, with the royal wearing several ties from the sustainable brand, Wilmok.

Related: Prince William Makes Chic (and Eco!) Style Statement in Cape Town

Later on Wednesday, five of the finalists will be awarded a $1.3 million prize each at a star-studded event, described by William's team as his "Super Bowl moment."

William has heard about their experiences over the last few days — mainly their involvement in the Earthshot Week’s Fellowship program, which helps them find solutions to grow and market their planet saving innovations. 

William emerged in the sunshine walking with CEO of Earthshot, Hannah Jones, and was taken for a walk across the lawns. He was then shown around by Werner Voigt, Garden Director, and introduced to representatives from each finalist.

Related: Prince William Wears 'Papa' Friendship Bracelet in Sweet Nod to His Kids During South Africa Visit

“It’s amazing just how much he deeply understands everyone’s solutions, which is testament to how passionate he is about this project,” Allen, who is the creative director of Natural Fiber Welding, tells PEOPLE. “He was really engaged and present. It is wonderful to have a conversation who is really present.”

“He was chatting with me a little bit about our regenerative supply chain work with smallholders in Thailand which is some of the biggest impact NFW can have. As a company committed to transitioning materials away from fossil fuels – something we need just as desperately as we need an energy transition away from fossil fuels."

After showing the prince around, Garden Director Voigt tells PEOPLE, “I love the fact he made time for everyone. It wasn’t rushed, it was very relaxed. There is genuine interest there in all the stories [the companies] had to tell about their innovations from around the world.”

“It seems to be his passion,” Voigt adds.

Voigt says they also spoke about the balance between the dependence on natural resources like fish and coast and the growing demand. “It’s such a fine balance," he explains. "He knows what’s going on around the world. When he met each finalist he would say. ‘You’re this company with this or that wonderful new products.’ He is engaged and he does his research.”

Related: Earthshot Prize Finalists Praise Prince William's Vision in Cape Town: A 'Coalition Builder'

William also saw a milkwood tree that his father King Charles planted almost exactly 13 years ago when he toured with the then Duchess of Cornwall.

“At the top there we were talking about the tree his father – yesterday to the day 13 years ago – and that in July we planted a new one because we had a severe storm with the highest record of rainfall. He was quite interested in seeing that. He said his dad ‘plants trees everywhere!’ ” Voigt adds.

“He just enjoyed the vista, which is unbelievable. And the weather of course,” Voigt says motioning to the clear blue sky. “He was saying about the rugby with the kids and it was raining and then it opened up for an hour or so, he could engage with the kids.”

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Also among those meeting the prince was Ninna Granucci, co-founder of another Earthshot Prize finalist, Ferment’Up. Earlier in the week, she told PEOPLE: “It is brilliant how [William] is using all the attention he can get to focus on the problems that we need to solve and the solutions we can use to do that. I am very grateful to him for bringing so diverse people together with the same goal of finding solutions for our climate.”

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Kelly Adams, CEO of Advanced Thermovoltaic Systems, which has developed a technology to capture waste heat and convert it into electricity, is another finalist who has been taking part in Earthshot Week, He told PEOPLE, “We’re the first company to design [a product like this] at this scale. The captured electricity will be used on-site for future power. It cuts down the electrical power a plant will be using too. It’s a paradigm shift for the industry.”

He commended William’s ability to bring people together and amplify a message that resonates globally.

“This is an amazing opportunity for us. We are trying to get out to society and show what's possible. When you’re at the forefront of innovation, that can take a long time," he said.