Leading national tree and horticultural organisations – the Woodland Trust, the Horticultural Trades Association (HTA) and the Royal Horticultural Society (RHS) - are making a renewed call to Ministers, and all levels of government, to act now to cool UK cities through green infrastructure, warning that repeated extreme heat is already reshaping daily life and risks becoming the new summer norm.
The warning comes after the UK saw record-breaking heat twice this year, with London recording an all-time May high of 35.1°C and the UK then experiencing provisional record-breaking June heat on three consecutive days during last week’s heatwave.
The organisations say the solution is already in front of us: more trees, more green infrastructure, and a stronger domestic tree-production sector able to supply the planting the country urgently needs.
The latest Met Office figures show why action cannot wait: the UK provisionally set a new UK daily maximum temperature record for June on 24 June, before it was exceeded on the following two days as the heatwave intensified. Temperatures reached 37.7°C at Lingwood, Norfolk, on 26 June, while the Mayor of London’s Heat Ready London plan warned that rising temperatures are already putting homes, schools, hospitals, care services and infrastructure under pressure.
With the next iteration of the government’s England Trees Action Plan due any day, the organisations are calling for decisive action to maximise green infrastructure and support domestic tree production. In a letter to the Minister for Nature, Mary Creagh MP, sent on 17 June ahead of the recent heatwave, the organisations which make up the Strong Roots trees alliance urged that two vital recommendations from the Strong Roots report are included, specifically:
- Conduct a feasibility study into what proportion of imported tree material could be produced domestically; and
- Use the study to develop a dedicated action plan for increased productive and ornamental tree production in England.
The Strong Roots report, published in October 2025, suggests that the UK government’s Net Zero Strategy, which requires 40,000 hectares of trees to be planted annually by 2030, is likely to be held back by barriers to domestic tree production, such as the lack of a designated action plan and a shortage of skilled workers.
The report stresses the essential role trees play in sustaining biodiversity, mitigating climate change and enhancing wellbeing. It makes recommendations to the Government on how to increase the availability of homegrown trees across England, Scotland and Wales.
A study conducted in Manchester found that, in full sun, concrete surface temperatures reached 40°C, whereas grass in full sun only reached 23°C. Adding an element of tree shade reduced the temperatures further, with concrete 12°C cooler and grass 9°C cooler. The annual value of the urban cooling services provided by the UK’s vegetation was estimated at £430 million in 2020, equivalent to around £547 million per annum in 2025 prices.
Fran Barnes, Chief Executive of the Horticultural Trades Association, said: “Green infrastructure is not a nice-to-have; it is essential climate infrastructure. The evidence is clear that plants, gardens and trees can make a measurable difference to how hot our streets, homes and communities feel. In dense urban areas, where hard surfaces trap and retain heat, trees and green spaces provide shade, cool the air and reduce the heat absorbed by buildings, roads and pavements.
“That matters because hotter summers are already changing how people experience towns and cities. If we want places that are safer, healthier and more liveable in extreme heat, we need to plan, grow and plant the trees and green spaces that will protect communities in the decades ahead. The UK tree sector is ready to be part of that solution, but government must give businesses the confidence to invest in the domestic production needed to deliver it.”
Andy Egan, Head of Conservation Policy at the Woodland Trust said: “Last week's extreme temperatures show how poorly prepared we are for a rapidly changing climate. While some communities sweltered, others were shaded by trees which cooled surface temperatures by more than 10°C. Everyone needs this protection, but millions of people live in tree deserts. The Government's new tree action plan for England should prioritise planting high-quality homegrown trees in these areas, protecting communities and restoring nature.”
Professor Alistair Griffiths, RHS Director of Science and Collections, said: “Extreme heat is no longer a future threat; it is here now, and our towns and cities are feeling the strain. The science is unequivocal. Trees are one of the most effective natural tools we have for cooling urban environments, improving air quality and supporting biodiversity. But to realise these benefits at scale, we must urgently grow, establish and provide long-term care for more resilient, home-produced trees. Backing domestic production, establishment and long-term care is not just an environmental necessity, it is an investment in the UK’s long-term health, wellbeing and economic resilience.”
