To the long list of London bridges – the beautiful, the utilitarian and the less than stable – could soon be added a crossing that is green, pleasant and thronged by birds and bees – as well as locals and tourists.

Plans for the UK's first garden bridge, crossing the Thames between the South Bank and Temple station, have moved a step closer with the creation of a trust to oversee the £150m project.

According to the Garden Bridge trust, the new crossing would feature not only shrubs, trees, plants, benches and even "intimate walkways", but would also serve as a direct link between the South Bank and Covent Garden and Soho.

The proposed 367 metre (1,200ft) bridge, inspired by actor Joanna Lumley's dream of "a place with no noise or traffic where the only sounds are birdsong and bees buzzing and the wind in the trees, and below the steady rush of water", will be designed by Thomas Heatherwick, who created the flaming and many-petalled Olympic cauldron.

If the public consultation goes well and the project wins planning approval, work on the bridge could begin in 2015 and be completed two years later. Illustration: Arup

The designer and horticulturist Dan Pearson, who will look after the leafy side of things, aims to create a garden that will change with the seasons and afford people a placid vantage point from which to contemplate the old and the new of the London skyline.

If the public consultation goes well and the project wins planning approval, work on the bridge could begin in 2015 and be completed two years later.

Lumley said the new bridge would provide more than just a river crossing for the weary commuter. "There will be grasses, trees, wild flowers, and plants, unique to London's natural riverside habitat," she said. "I believe it will bring to Londoners and visitors alike peace and beauty and magic."

Thomas Heatherwick said the project would bring together long-divided areas of the capital. Illustration: Arup

Heatherwick, meanwhile, said the project would bring together long-divided areas of the capital. "The city on the north bank and the historic district of Temple is almost completely isolated from the river by the dual carriageway of the Victoria Embankment that slices its way along the north bank and – other than its wonderful view – Waterloo Bridge is surprisingly unfriendly for pedestrians," he said.

"There is now an opportunity to connect London together better, to give Londoners a huge improvement in the quality of pedestrian river crossing in this area, to allow us all to get closer to the river and at the same time to stimulate new regeneration possibilities at both ends where it lands."

Map showing location of proposed garden bridge

The trust, which has been set up to oversee the project, is in the process of seeking charitable status and will embark on a fundraising campaign to raise the tens of millions needed to build the new bridge.

But it said the idea had already attracted "considerable interest and support" from private donors.

"This is the first major milestone for the project and marks a very clear intent to create a new landmark for London," said the trust's chair, Lord Davies.

"The scheme has been shaped and developed into a proposal that will contribute significantly to the future of London's development and we are committed to ensuring the Garden Bridge will be something London can be proud of."