Waltham Forest the first Council to install the first permanent City Trees in London

31 December 2019


City Tree
  • Council partners with Evergen to bring the revolutionary system permanently to London.
  • CityTree is the World’s first biotech pollution filter and uses living plants to filter toxins from the air.
  • With the cleaning power of 275 trees, will contribute to improving air quality.


Waltham Forest Council has achieved a London first and permanently installed two City Trees in Leytonstone. CityTree is a free-standing outdoor air cleaning system that uses the power of biotechnology to emulate the pollution-reduction benefits of 275 urban trees.

The City Trees, or moss trees, are the world’s first biotech pollution filter and use living plants to filter pollutants from air, creating microenvironments of cleaner air that benefit residents and passers-by.

Cllr Clyde Loakes, Waltham Forest Council’s Deputy Leader and Cabinet Member for Environment said: “Waltham Forest Council has been tackling climate change for over a decade. Installing two City Trees is one of the many measures we are taking to improve air quality in the borough.

“The City Trees are cutting-edge technology with biotech filters, using living plants and different types of mosses to capture toxins and remove pollutants from the surrounding environment to produce clean air. It’s the equivalent of planting 275 trees.

“The City Trees at Leytonstone tube station and another on Leytonstone High Road are permanent additions to the borough and London in our fight against poor air quality. I am delighted that Waltham Forest is again leading the way in improving air quality and tackling climate change in London.”

The locations of the City Trees experience significant air pollution. The Leytonstone Station site is at a bus station and sits on top of the A12 where there are the highest levels of nitrogen dioxide in the borough. The Thatched House site is at the junction of two heavily trafficked roads – Leytonstone High Road / Leytonstone Road and Cann Hall Road / Crownfield Road.

The City Tree is a self-sustaining structure that contains a water tank, with automatic irrigation and plant sensors all powered by on board solar panels and batteries. The different types of moss bind environmental toxins such as particulate matter and nitrogen oxides while at the same time producing oxygen. Cutting-edge integrated technology can deliver comprehensive information on air filtering performance and status as well as environmental data on the CityTree’s surroundings.

Waltham Forest has been leading the way in tackling climate change and improving air quality, not just in London but across the UK. The Enjoy Waltham Forest road and public realm improvements to promote walking, cycling, and sustainable transport have seen 27 kilometres of segregated cycle lanes built, cycle usage increased by 103 per cent, and car usage reduced by seven per cent. The number of Waltham Forest households exposed to dangerous levels of NO2 reduced from 58,000 to 6,300 and children born in the borough since 2013 are expected to live six weeks longer (Kings College AQ Report).

The Council declared a climate emergency in April 2019, at a Full Council meeting, and committed to launching a Climate Emergency Commission – the first in London - to help shape their local response to this global challenge and to produce a set of policy ‘asks’ for regional and national politicians.

The Commission comprises of experts from across the energy, waste and environmental sectors to bring their knowledge and expertise to help the Council in the next phase of tackling the climate emergency.

The Commission will inform the Council’s Climate Emergency Strategy and make recommendations for how, as a borough, the Council can work together with residents, businesses and partners to tackle a global issue in a local context.

Read more about the Climate Emergency here