New gardens at seven high-profile sites such as the National Theatre, built by world-famous names in horticulture, may form a counterpoint event to the RHS Chelsea Flower Show.
The Cityscapes project will mark the inaugural Chelsea Fringe Festival in May.
The gardens featuring designs by Tom Stuart-Smith, among others, will be open for four months and designs are being finalised.
"We want to expose other creative industries such as art and architecture to what garden design is all about," said artist Adolfo Harrison, who launched the project with garden writer Darryl Moore.
"Our gardens will respond to their sites, which unlike Chelsea will not be controlled spaces. They will be open to vandalism and theft. This is very much an urban project," he added.
Garden turned shoe-designer Christian Louboutin is working at the Design Museum to tie in with a big show of his work and will work with Andrew Fisher Tomlin. Andy Sturgeon is taking on a pod on the London Eye.
Meanwhile, Sarah Eberle is designing a roof garden at the Architecture Foundation, Swiss landscape architect Vogt is working at Tate Modern, Tony Heywood at Old Vic Tunnels and Todd Longstaffe-Gowan at the Imperial War Museum.
The Cityscapes event will run from 19 May to 9th September 2012.
Meanwhile the Chelsea Fringe runs from 19 May to 10 June. Events include community horticulture projects, floral boats on the Thames and museums festooned with plant-themed artworks.
Organisers hope sponsors will meet the costs of the gardens and have recruited advertising giant Ogilvy to handle the media.