This briefing from the Royal Horticultural Society (RHS) outlines the findings of a literature review carried out by researchers based in the RHS, with assistance from the Universities of Reading and Sheffield. The briefing concludes that gardens have several important roles in urban areas. Garden plants and trees help cool the air in towns and cities. This has several benefits, including reducing fatalities in heat waves, lowering the need for air conditioning. Conversely, urban gardens can help to insulate homes in winter, with particularly significant impacts in the north of the UK. Garden plants and trees also intercept rain, slowing runoff and reducing the pressure on urban drains, which helps to prevent urban flooding. The impacts on improving urban biodiversity and supporting human health are also explored.
http://www.rhs.org.uk/Gardening/Sustainable-gardening/pdfs/RHS-urban-gre...