William and Kate – addressed as the Earl and Countess of Strathearn when in Scotland – made vegetarian burgers, repaired bicycles, and helped to re-wild a grassy bank with the boys at Alexandra Park in Dennistoun, Glasgow, while world leaders met at Cop26 nearby.
The workshop was part of the international Promise To The Planet campaign, which aims to teach 57 million Scouts how to lead more environmentally friendly lives.
Both sporting red poppies on their lapels, the royal couple had travelled to Scotland by train and were driven to the park in an electric Jaguar I-Pace, where they met 20 members of the 105th Glasgow Scout Group.
Kate, 39, who is joint president of the Scouts, jokingly threatened to slap her husband’s face with her dirty gloves as they made wildflower seed-bombs with the youngsters.
While making vegetarian burgers with the boys, William asked if they had ever tried one before and whether they liked them more than meat burgers.
Meanwhile, Kate, wearing a Scout neckerchief with a khaki gilet and black trousers, helped to prepare ingredients and asked the boys: “Do you get enough veg at school?”
The couple helped the youngsters tighten bike brakes and fix loose handlebars before joining the children mixing flour, soil and wildflowers into seed-bombs, which they threw at a grassy bank to encourage natural growth.
Taking advice from one Scout about re-wilding, William, who wore a navy jumper and trousers, told him: “You’ve done this a few times before, haven’t you?”
“You’re doing well. You’re leading us very well.”
Eddie O’Rourke, who supports Scout groups in Glasgow and Lanarkshire as district commissioner, described the royal couple as a “real inspiration” to the boys.
He said: “They were a real inspiration to all the Scouts who are working hard to make changes to protect the planet.”
The royal couple also met 12-year-old Cop26 ambassador Lewis Howe, who is among 26 Scouts who have been selected by the Government to showcase how ordinary people are taking action to combat climate change.
Lewis, from the 1st Laurencekirk Scouts in Aberdeenshire, has been challenging Scottish schools to cut food waste by using surplus stock to provide meals for vulnerable people.
He said: “I have been inspired by my Scouts leaders and the amazing actions of my fellow Scouts.”
Kate is the first woman to hold the role of president of the Scouts, which she shares with Prince Edward, the Duke of Kent.
Members of the royal family will take part in a series of events at Cop26, and on Monday evening the Prince of Wales, the Duchess of Cornwall, and the Duke and Duchess of Cambridge are due to attend an evening reception with world leaders.