The garden was declared by the Norfolk Island and Commonwealth Governments in 1986 to provide a place where specimens of Norfolk's unique flora could be appreciated.
The plant collection has over 150,000 plants with approximately 140 families, 700 genera and 2000 different species represented. Although South Coast Botanic Gardens flora has species from all over the globe, it is particularly rich in plants from Australia and South America, whose similar climates make South Coast ideally suited for plant introduction programs.