The council gardens are managed by grounds maintenance and landscape construction company Continental Landscapes. They aim to offer "an oasis of calm for those escaping the hustle and bustle of Oxford Street, Piccadilly and Park Lane", the company said in a statement.
The gardens are filled with ornamental bedding plants, shrubs, formal lawn and a number of mature London Planes. They also contain a bronze drinking fountain in the shape of a rearing horse, designed by Sir Ernest George and Harold Peto.
Steve Mills from Continental Landscapes said: "The award is recognition of the high standards of maintenance achieved by our dedicated team. It is heartening to know that the site is so loved by residents and visitors to Mayfair."