A national movement must be formed to reconnect children with nature, according to Children in Scotland.
The children's charity fears that learning is being damaged because children are too removed from the natural environment.
"Children's inactivity, a decline in green space, the growth of car dependency, and anxiety about child safety, are all elements of modern life that are causing children to become disconnected from the natural world, which is a vital tool for fostering creativity and learning, and in shaping adult attitudes," said Karen Mountney, the head of programming.
Children in Scotland has called on the Scottish Government to focus on "nurturing through nature" in the early years, and points to ongoing examples of this type of learning at home and abroad.
Inveraray Primary has its own outdoor classroom, with a turf roof that is partially open to the elements, designed with the help of pupils.
Scottish "forest schools" encourage an appreciation of the natural world through visits to special woodland sites, where children can master tasks of increasing complexity and learn social skills.
In the Italian city of Verona, nursery teachers embark on "adventures" in the local natural environment to develop children's independence, confidence and self-esteem.
"We believe there is a need to pull together to create a national movement which connects innovators and practitioners in Scotland and internationally," Ms Mountney said.
"There is some very impressive work happening at an international level that could inspire new ideas here."
The use of nature in learning is the subject of a Children in Scotland publication, Adventures in Nature.