The race is on to materially improve the resilience of towns and cities around the United Kingdom in the face of increasing extreme weather events. As hotter summers with more intense rainstorms progressively impact everyone from big businesses to local authorities and householders, scientists, horticulturists and urban planners are gathering at the Royal Botanic Garden Edinburgh (RBGE) to launch Plants with Purpose, a £500,000 evidence-based initiative to prove positive changes can be in place by 2029.

At the core of the initiative is a partnership approach to researching and demonstrating the impacts of plant choice and location on how urban spaces react to differing weather patterns. And in what way, at the same time, this investment is needed to improve the health and wellbeing of our urban dwellers and workers

The goal is to have a useable reference library of scientific data and horticultural advice - real-life actionable toolkits - in place for everyone to make informed choices on how they can mitigate the effects of climate change using plants. These range from achievable ways of absorbing flash flood water, to moderating extreme temperatures in buildings, and providing the right conditions for endangered pollinators.

Plants with Purpose is being headed up by Raoul Curtis-Machin, Director of Horticulture and Visitor Experience at RBGE, who has an extensive background across the environment, horticulture trade and culture sectors. He explained: “The twin threats of climate change and biodiversity loss are causing real social and economic shocks for urban communities around the United Kingdom. We need to start moving much faster to adapt to these challenges. That means changing our mindsets around city living and utilising the natural resources we have been diminishing over centuries and dramatically speeding-up that decline for decades.

“Traditional urban planning and grey infrastructure offer limited opportunities for managing hydrometeorological hazards such as flash flooding and heat waves and create negative impact on wildlife and insects, significantly our much-needed pollinators. Natural ecosystems offer a multitude of benefits, including temperature regulation, flood risk management, biodiversity recovery, ecological connectivity, and improved human health and wellbeing. Yet, they continue to be degraded as urban settlements expand and densify”.

Working in partnership with Heriot Watt University during the preliminary phases of Plants with Purpose, the RBGE team has developed a clearer understanding of the hydrology of urban environments and the demonstratable benefits that can be achieved in even short periods of time. This includes dramatic changes to flood conditions brought about by seemingly humble rain gardens and storm water butts.

Dr Daniel Green, Assistant Professor of Nature based Solutions at Heriot-Watt University, outlined the importance of this work: “Millions of people are affected by flooding every year in the UK. The annual cost of the damage comes to more than a billion pounds and this is largely concentrated in urban areas. Climate change is causing more frequent and severe rainfall events and this will only worsen in the future, so we need to adapt to our changing weather conditions.

“One of the ways of solving this urgent issue can be found by adopting Nature-based Solutions and working with natural processes to help slow and store water in our urban areas. These can be larger-scale interventions, such as rain gardens or bio-swales, or smaller, more focused, source-level adaptions. In addition to helping us manage urban flooding, Nature-based Solutions also offer additional benefits such as biodiversity improvements, water quality treatments and public amenity value, making them much more appealing and potentially cost-effective than traditional ‘grey infrastructure’ systems.”

The initiative and growing partnerships will be managed by RBGE scientists Dr Emma Bush and Caitlyn Johnstone, with horticultural advice being led by William Hinchliffe. Emma Bush concluded: “Transformations to our towns and cities will only come about if we join together across society to make the big scale changes. Fundamentally, we need to re-imagine the role of urban nature and our relationship to it, because working with nature will benefit us all. It doesn’t need to be difficult, and everyone can join in. This is our opportunity to get it right, now let’s get on with it!”.