The event from 22 to 23 September, better known for throwing open the doors to private or obscure buildings, is to shed light on spaces such as Walthamstow Wetlands and the transformed railway lands of King’s Cross.
Also on show is the Grenville Community Gardens in Islington, which reveals how good design can revitalise the capital, make it a more enjoyable and deliver diversity and a sense of place in our busy city.
"Investment in landscape is changing the face of London and delivering exciting social, environmental and economic benefits," said a spokeswoman. "This year’s festival will be unprecedented in breadth, scale and reach."
Gardens include 20 Triton Street, a 22,000 sq ft green roof that attenuates around 2.4m litres of water every year and providing a bio-diverse habitat for wildlife. It’s also home to London’s largest insect hotel.
Granary Building and Square, King’s Cross, mixed-use development landscaped by Townshend Landscape Architects, including 1,080 water jets, terraced steps to the canal and two contemporary pavilions.
"From large-scale public realm and urban regeneration to green roofs and small, community-run edible landscapes visitors can join landscape architects on walks and talks and go behind the scenes of some the most exciting green spaces."
She said the two-day event was a good opportunity for people to learn how planners, architects, landscape architects and engineers worked together to create places of beauty and diversity.
Visit this Landscape Map, http://www.openhouselondon.org.uk/landscape/ , to discover 20 special landscapes. Or visit http://www.openhouselondon.org.uk/landscape/ for more information on the Open House London landscape programme.