WATCH: Prince George breaks out in tears after being yelled at by Kate Middleton
"Over the past months, Prince George, Princess Charlotte and Prince Louis have helped The Duchess gather moss, leaves and twigs to help decorate @The_RHS Back to Nature Garden. Hazel sticks collected by the family were also used to make the garden’s den," the statement from Kensington Palace also read.
Kate collaborated with architects Andrée Davies and Adam White to create the garden, which featured a tree-house, a rope swing, edible plants and a green and blue colour scheme.
The 37-year-old also left a hand-written note in the garden, which said: “Boulder hopping in the Lake District”, and signed off the note with “Catherine”.
Kate, who hoped the garden would encourage future generations to enjoy the great outdoors, told the BBC:
“I really feel that nature and being interactive outdoors has huge benefits on our physical and mental wellbeing, particularly for young children.
“I really hope that this woodland that we have created really inspires families, kids and communities to get outside, enjoy nature and the outdoors, and spend quality time together.”