The horticulture industry has not yet realised opportunities to green up areas in the public realm, sustainable planting design expert Professor Nigel Dunnett has said.
The RHS invited the University of Sheffield lecturer to create a garden for its Hampton Court Palace Flower Show as part of its Greening Grey Britain campaign, which urges the public to plant up their front gardens.
Created for St Mungo's homeless hostel in Bristol, the walk-through Community Street garden started with an expanse of concrete and gravel and expanded into a series of gardens filled with messages about the positive impacts of planting.
The absence of lawn left room for a food forest, rain gardens, meadows, raised planters and a drought-tolerant driveway.
Interactive features include thermal imaging, a smoke machine representing air pollution, a water pump and the chance to "plant" a horticultural pledge.
A streetscape includes rain gardens - to absorb run-off from the road - as well as cycle racks, seating and rubbish bins disguised beneath roof gardens.
The latter was aimed at "public realm" groups such as schools, supermarkets and city councils, which Dunnett said need encouragement to increase planting and biodiversity on their patch.
"We're saying there's a huge horticultural opportunity to make these places beautiful, which I don't think horticulture has grasped yet," he added.
Visitors to Hampton Court are already horticulturally minded, but Dunnett wants even the green-fingered to do more to improve biodiversity in their gardens. He also hopes media publicity around the garden will reach a wider audience and "start a revolution" of greening to combat the plague of paving across the country.
The 430sq m garden was made in partnership with the BBC and designed by Dunnett and The Landscape Agency, with contractor Landform UK carrying out the work.
Hortus Loci supplied most plants and loaned trees and shrubs for the show. Marshalls donated hard landscaping products, Green Roof Shelters provided roof-planted cycle racks and bin stores, and meadows came from Pictorial Meadows and Lindum Turf.
Climate change - Permeable paving backed
Government advisory body, the Committee to Combat Climate Change (CCCC) has added its voice to calls to reverse the trend of paving over front gardens, telling Parliament it must do more to force householders to use permeable paving.
Householders need planning permission to cover more than 5sq m of front garden with impermeable paving. But most local authorities are failing to enforce the rules, said the CCCC.
RHS research shows paved-over front gardens have tripled over the past decade. But permeable paving sales remain low, suggesting many householders flout the law.
The CCCC said halting the decline in urban green space would have multiple benefits for climate change adaptation. It called on the Department for Communities & Local Government to work with local authorities to make changes.