The Elephant and Castle-based neighbourhood hub has received a boost in its fundraising efforts, following a donation from Sadiq Khan's office.
The project aims to transform two underused courtyard sites into gardens, a community centre and workspace studios in the Lamlash Garden.
The Lamlash Garden team said: "The Castle Place project is a vital scheme for the community, where families and friends can enjoy a fantastic green space in the heart of London. We promise to deliver long-term, affordable workspaces for the creative industries, as well a great community centre for residents and visitors alike."
By turning Lamlash Garden, a reclaimed public street, into a community garden, new cycling routes will be accessible to people using the space.
"We've already surpassed one degree of global warming," said Kristen Buida, manager of the London Climate Change Partnership.