"All of these gardens have unique stories and novelties, and deeply explore the sense of space, materials and charm they produce," Cai said. The organizers said they hope the different styles of gardens and flowers from all over the world can be exhibited, creating a magnificent "world garden". This year, the expo expects to receive some 3 million visitors, according to the organizers.

Shanghai Mayor Gong Zheng said the flower expo is a push for the city's green development and it is expected to become an example of sustainability and cooperation between domestic and international parties.