"The quarry dates back to the 1700s and still has years of extraction left in it," said Farley. "The beauty of this stone is in the many forms it can be processed once extracted, which have provided the various textures I have used.
"It would be easy to use the usual red, white and blue," he said of his garden at the East of England Showground, Peterborough. "I wanted to create an illusion of time by combining hard and soft landscaping in a different way."
Six concentric circles represent the six decades of the Queen’s reign in a similar way rings in a tree trunk tell its age. The circles rotate between the rock and the planting, which was supplied by Bettaland of Peterborough.
Showing the Prince the garden was Julie Boyce, area business manager of Lafarge Aggregates, which donated landscaping for the temporary installation from its Dry Rigg quarry, North Yorkshire.
The garden design will be moved to the Royal Sandringham show on 27 July, where the Dry Rigg rock will remain.