Last Updated on 10 September 2026
2026 has marked one of the driest summers since records began, putting a significant strain on our urban trees across London. While many of the recently planted young trees have not survived, the damage to mature traditional trees, including oaks, may only show over the coming years. The current felling of mature trees affected by disease across Cannizaro Park is a case in point.
With more extreme weather patterns – such as El Niño – set to become the norm – over two thirds of London’s public realm tree population could struggle, according to a report funded amongst others by the GLA.
The stated aim of the Mayor of London is to increase tree canopy cover in London by 10% from 2016 levels. As we discussed in our article ‘How to Cool our Cities’, trees are essential for moderating summer heat as well as improving local air quality. The GLA has embarked on a research project to determine which tree species are more resistant to future climatic conditions with results set to be released next year. As discussed in a recent BBC article, the Charity Trees for Cities is already experimenting in London with replacing native species such as Alder with Italian Alder, which so far appears to be more resilient to climate change, along with Ginko and European nettle trees.
A report released in November 2025, titled Future Climate Suitability of London’s Public Realm Trees, highlights:
If no changes are made, in total, 73% of London’s public trees may struggle to thrive or survive as the climate changes.
Publicly owned trees deliver around 60% of the ecosystem services London’s urban forest provides, this includes cooling, air purification, and stormwater management. The resilience of London’s overall public tree population is critical to sustaining the environmental and cultural benefits Londoners rely on.
The report makes the following recommendations:
- Enhance the health of existing trees.
- Strategically diversify London’s urban forest.
- Fund tree establishment, not tree planting.
- Adopt a London tree data standard.
- Collaborate with tree nurseries.
- Develop a strategic mechanism to get novel plant material into horticultural production.
- Address gaps in plant trait data.
- Evaluate potential canopy cover impacts of species climate suitability.
- Develop London-wide strategies and structures to manage the whole of London’s urban forest.
- Apply this analytical framework to other cities and regions.
The report can be found on the GLA’a London Tree Map site, which provides many useful details on the capital’s 1.1 million public realm trees.
Trees for Cities highlights in an article published on 26 August the importance of continuing to water young trees. While rain has finally returned, it will take a significant time for ground moisture levels to recover. It encourages the public to become a ‘tree watering champion’.
Key recommendations
- Give young trees at least 50 litres per week in warmer months
- Water your trees in the early morning or late evening when it’s cooler to avoid losing water to evaporation
- Use watering pipes and bags where available to give young trees the best access to water
- Add mulch to the base of your trees. It helps retain water, keeping the ground moist and also prevents root competition
- If you can, source your water sustainably. Rainwater is a great option, but grey water from your washing up, baths or showers works just as well!
The Wimbledon Society is working to spread the word about the importance of retaining trees and plants in our private front and rear gardens as well as in public spaces. Given the challenges posed by our changing climate, we will continue to highlight best practices for caring for our existing trees and how to establish resilient gardens and green spaces in a warming and dryer climate. If you have examples of local best practices, we would like to hear about them (info@wimbledonsociety.org.uk). Finally, if you are not already a member of the Wimbledon Society, please consider joining us and help us amplify our voice on this important issue.
