The Imperial Wharf project, built by property developer St George, includes sensory and roof gardens, parkland and a riverside walk.
The 385m riverside walk and intensely-managed sensory gardens make it one of the biggest and most extravagant public green spaces to be opened in the capital.
St George has not released any figures on the cost of the development, but a section 106 planning agreement required it to help pay for a new overland rail station before permission was granted. The company contributed £4.8m to build the recently-opened Imperial Wharf station.
The London Borough of Hammersmith and Fulham also said the developer must allow public access to the gardens before it would grant permission for the mixed-use development, which includes 1,800 luxury apartments.
But St George went beyond the agreement and, with the help of architect and designer Broadway Malyan and SJM landscapes, created a public park on the site of the former Fulham gasworks in an area desperately lacking green space.
SJM partner Steven McBirney oversaw the installation of all soft landscaping and his company's team of five will be in charge of maintaining the area.
He said: "This compares very favourably with some public sector developments. It has been a great project and we are pleased with what we have achieved."
The park and gardens include more than 18,500 shrubs, 14,500 perennials and 110 trees. Everything was sourced in the UK except the trees and each section of the green space is designed to be distinct and yet comfortably connect to the next.
Broadway Malyan associate director Allan Cox helped design and oversee the 10-year project. He said: "It is rare to have such an intensively-managed garden in a development such as this but the results speak for themselves."