With almost 85% of people in the UK living in urban areas, and communities facing rising temperatures, extreme weather, air pollution and biodiversity loss, we need thriving urban trees more than ever. Here are ten reasons to plant more — and care for the trees we already have.

1. They produce oxygen

If trees produced free Wi-Fi, we would probably be planting them everywhere. What they do produce is oxygen: every leaf acts like a tiny solar-powered factory, using sunlight to turn water and carbon dioxide into energy for growth and releasing oxygen along the way. It is an extraordinary everyday process — and just one of the many reasons trees matter in our towns and cities.

2. They sequester and store carbon

Trees take in carbon dioxide as they grow and store carbon in their trunks, branches, roots and surrounding soil. This makes trees and woodlands important carbon sinks and part of the wider response to climate change. To put that into perspective, it's estimated that 2,367,000 tonnes of carbon is stored in London’s trees alone, with an estimated value of £147million to the UK's economy.

It’s thought that globally our forests, plants and soil absorb around 30% of all carbon emissions generated by the burning of fossil fuels and other human activities. 

3. They support the management of air pollution

Urban trees can help manage air pollution when they are planted in the right places. Most people know that trees absorb carbon dioxide, but they can also help remove other pollutants from the air. Their leaves, bark and branches can trap tiny particles from traffic and other sources of pollution before we breathe them in — making towns and cities healthier places to live.

4. They support urban flood risk management

A mature tree can drink up to 900 litres of water every day, as well as capture rainwater on the surface of its leaves. Their roots also reduce soil erosion in the ground and slow the filtration of water into our cities' drainage networks.

This is particularly important in cities where a large proportion of the ground surface is made up of impermeable materials, like tarmac and concrete. When we get a sudden downpour, this can quickly cause flash flooding if the water has nowhere to go. Trees to the rescue!

5. They’re keeping things cool

Trees cool cities by casting shade and releasing water vapour through transpiration. This reduces the heat absorbed by roads, pavements and buildings and makes streets, schools and parks more comfortable during hot weather. As UK summers become hotter and heatwaves more frequent, that natural cooling is increasingly important for people living in towns and cities. 

Read more about how urban trees turn down the heat and help tackle the urban heat island effect, where towns and cities become much hotter than rural areas.

6. They support our urban wildlife

Urban trees are habitats in their own right. Their flowers, fruit, seeds, bark, branches and roots provide food and shelter for birds, bats, bees, butterflies, fungi and many other species. Planting a diverse mix of suitable trees can strengthen urban biodiversity and connect fragmented green spaces, creating corridors for wildlife.

7. They’re good for our mental health and wellbeing

Trees don't just improve our physical environment, they also do wonders for our mental health! Access to welcoming green spaces can encourage people to spend time outdoors, be active, meet others and connect with nature.

Being around nature, specifically trees, has also been shown to reduce the levels of cortisol in our brains. This is otherwise known as the stress hormone, and lowering it can help to reduce the symptoms of anxiety and stress. 

8. Our urban trees are getting old

Many of the mature trees that shape our towns and cities were planted decades ago. They provide the greatest shade, habitat and environmental benefits, but they won't live forever.

Because trees take years to mature, we need to plan ahead: protect established trees, plant the next generation and care for young trees so they thrive. In 2026, we celebrated planting our two millionth urban tree — but lasting impact depends on establishment as well as planting.

We've been planting since 1993 and have watched our young whips grow into magnificent urban trees, but we must keep planting more, and protecting the ones we do have.

9. Everyone’s heading to the cities

Almost 85% of people in the UK live in urban areas. That makes access to trees and quality green space a daily health, climate and equity issue — not a countryside concern.

Yet tree cover is not shared equally. Planting where canopy cover is low can help bring cleaner air, cooler streets, wildlife and access to nature to communities that stand to benefit most.

10. Because we love them!

Trees shape the identity of streets, parks and neighbourhoods. They hold memories, mark the seasons and make everyday journeys greener and more comfortable. Imagine your favourite tree-lined street without its trees: most of us would choose more green, not more grey.

Donate today to help us plant and care for urban trees where they are needed most. Let's create healthier, greener and more resilient places for people and nature.