Prince Charles’s back garden at Highgrove in Gloucestershire was opened up to 50 pupils last week and his horticultural secrets laid bare.

The amateur gardeners from primary schools around the country were given guided tours of the 15-acre private garden, much of it designed by the Prince.

From the more formal terrace, where the royal easel is often set up, to the topsy-turvy topiary avenue where Highgrove’s 12 resident gardeners are given free rein to design whatever they like, the children were given a running commentary on the Prince of Wales’s outdoor tastes.

The 10 and 11-year-olds trampled down royal molehills, walked among a herd of black sheep grazing freely on grass around the house and picked rosemary from the kitchen garden.

Guides more used to briefing visitors using Latin names for the many rare species at Highgrove customised the two-hour tour for their young audience.

“His Royal Highness is very much into toadstools,” one guide said as she showed her group a collection of almost a dozen wooden toadstools stuck in the ground. “He keeps us very much on our feet and tells us to keep a count of how many there are, and just a few weeks ago another one arrived out of nowhere.”

On being shown the magnificent creepers that envelop parts of Highgrove House the question on the children’s lips was: “How does he see out of the windows?”

They were not the only ones to wonder. One guide, who had asked the Prince the same question, was told “I can see exactly what I want to.”

Michael White, a 10-year-old from Sibford Gower endowed primary in Banbury, Oxfordshire, said: “It was amazing to see Prince Charles’s garden. It was really natural and not as tidy as I thought it would be. I really liked all the chairs cut out of tree trunks.”

Nicholas Chesher, in the same year at Sibford Gower, said: “It was like a story book, there was so much. My favourite bit was this huge waterfall through limestone rock with hundreds of holes in it which had plants growing out of the top of it. Any way you looked you could see different things in the distance.” Friends Katie Ascott and Tori Reynolds, both 10, at the same school, were more interested in a small figure of a leprechaun lying on a secluded bench. “Look, he’s got a doll in his garden,” they giggled to each other.

The groups saw Princes William and Harry’s old tree house, and the Sanctuary, a small place of worship which the Prince had built to the measurements of the “Royal Inch” - the distance between the tip and the knuckle of Prince Charles’s thumb.

The day at Highgrove was part of an awards ceremony for the finalists of a nationwide competition set up by the charity Reep (the Religious Education and Environment Programme) to design a school garden with spiritual and environmental influences.

The overall winner was Parklands primary in Northampton, which received Pounds 1,000 to start building the garden pupils had designed for a hospice next to the school. Another 13 schools received pound;500 towards implementing their designs.

* newsdesk@tes.co.uk