The Mediterranean climatic region is called garden of the world because this name is affiliated with its climate and the plants which correspond with it.
The Mediterranean climate happens in areas of Southern, South Western Australia, Central Chile, Coastal California,Western Cape of South Africa and lastly the Mediterranean Basin.
Why is this called the garden?
Since these areas are affiliated with the cool seasons of winter and spring that accompany soft rains which allows the growth of flowers in various shapes and sizes and colors. Thus, this is called the garden of the world. Because of its availability and variety of flowers.