The method involves providing a lawn (2) that is surrounded portion wise on an upper side by a downward open room (4), which surrounds on all sides of the lawn. Carbon dioxide gas is fed into the room and the lawn that is covered by the room subjected with light with illumination device (14), where the carbon dioxide gas is fed within the highest range of the room. The gas concentration is measured and the gas supply is controlled. An independent claim is also included for a device for growth acceleration and regeneration of a lawn.
