Take a close look at the blueprint city garden of the future, designed to meet the increasing challenges of both climate change and rapid urban development.
Created around a fictitious high-rise apartment block, the garden, part of the Royal Horticultural Society’s Greening Grey Britain campaign, will be displayed at this year’s Chelsea Flower Show where it will, hopes pioneering designer Nigel Dunnett, have unusually broad appeal.
“Gardens are now thought of as very important in selling a new development, to the extent that the landscape is as important as the building,” says Dunnett, professor of planting design at the University of Sheffield, but best known for the spectacular pictorial meadows at the Olympic Park and the dynamic planting at the Barbican’s new roof garden.
“That’s what I want to highlight: the change that tends to happen in high-end developments, but needs to be in the mainstream of horticultural thinking, too. I hope that by showcasing realistic and sustainable ideas that are relevant to home gardeners, community groups and crucially to urban residential and commercial developers, that we can make a difference.”
Adapting to increasingly extreme weather conditions is central to Dunnett’s design. Rain gardens — dips and hollows planted with resilient plants such as rudbeckias, euphorbias and astilbes — allow water to drain down into the soil, while shallow wetland areas, supporting decorative waterside grasses planted in slices of concrete pipes, capture rainwater to irrigate the garden.
Walkways are of permeable paving, random-cut from recycled municipal concrete slabs. “We’re hoping to start a crazy paving revival,” says Dunnett. “The point is to use everyday materials that anybody can use.”
Dunnett is renowned for what he calls “low-input, high-impact planting”, which features throughout the space, and is designed to combine colour and beauty with a long season of flowering and little maintenance. Plants are selected for their drought-resistant properties as well as abilities to soak up pollution.
“It’s sustainable planting,” he points out. “The trees and shrubs are all productive. The purple elder trees that feature prominently throughout the garden, for instance, produce both fruit and flowers.” He adds that the garden highlights the range of planting opportunities for balconies and backyards as well as large gardens and social spaces.
Plants grow everywhere, in pockets on the outside walls, in deep boxes around the edge of balconies and vertically, on metal grids at ground level. “Climbers on trellis are simpler than living walls, and don’t have the intensive watering system,” he points out.
Using space wisely is a key issue that Dunnett has further addressed by introducing platforms for planting in all the structural features. Thus, plants grow up the supports of the bike store and cover the roof of the bin store, while an 8ft-long communal meeting table, set in shade by the apartment block, has fruit trees growing through it so you can reach up and pick an apple off the branch.
Sustaining wildlife is an important function of the urban garden, and, believes Dunnett, you can encourage pollinators simply by incorporating a diversity of flowering plants. “You don’t need to stick rigidly to native planting to bring in wildlife.”
In this garden, log piles act as wildlife habitats and “creature towers”, multi-layered structures that reflect the apartment block, provide cosy refuge, along with nesting boxes and bird feeders.
Our back gardens have always been decorative, but the message is that now they need to do more. “With pollution levels dangerously high in cities like London, Glasgow and Southampton and flash-flooding causing devastation, we all need to embrace the fact that plants help mitigate against some of the biggest environmental threats facing us today,” says Dunnett, who, on a lighter note, is renowned for his love of bright, colourful planting.
“Particularly in urban gardens, the use of colour has such an uplifting response. Although the RHS campaign is called Greening Grey, really it should be called Colouring Up Grey, because it’s all about bringing energy, vibrancy and joy into places that don’t have them.”