A plant that absorbs pollution from cars has been found - the science explained

Thursday, 18th February 2021, 12:52 pm
Updated Thursday, 18th February 2021, 12:53 pm
The bushy, hairy-leafed cotoneaster is a “super plant” that can soak up pollution of busy roads, according to horticultural experts (Photo: RHS)

The bushy, hairy-leafed cotoneaster is a “super plant” that can soak up pollution of busy roads, according to horticultural experts.

Scientists at the Royal Horticultural Society (RHS) published a paper that looked at the effectiveness of hedges as air pollution barriers, and found that in traffic hotspots, the cotoneaster is at least 20 per cent more effective at absorbing pollutants compared to other shrubs.

According to a recent RHS commissioned survey of 2,056 adults, air pollution affects one in three people (33 per cent) in the UK, and poor air quality has been declared as the largest environmental risk to UK public health.

‘The cotoneaster traps 20% more emissions’

Dr Tijana Blanusa, research lead for the paper and RHS Principal Horticultural Scientist, said: “On major city roads with heavy traffic we’ve found that the species with more complex denser canopies, rough and hairy-leave such as cotoneaster were the most effective.

“We know that in just seven days a one metre length of well-managed dense hedge will mop up the same amount of pollution that a car emits over a 500 mile drive.

“We estimate the Cotoneaster franchetii traps 20 per cent more emissions than other hedges we have tested so would be ideal along busy roads in pollution hot spots.

“For other areas where encouraging biodiversity and pollinators is key, a mix of different hedge species would be recommended.”

In the last 10 years, RHS scientists have intensified their research to find solutions to help ease environmental issues, such as air pollution, heatwaves and localised flooding, in order to amplify the positive impact of gardens and green spaces on the environment.

‘Plans can help alleviate numerous environmental issues’

Professor Alistair Griffiths, RHS Director of Science and Collections, said: “RHS science has shown that underlying traits of certain plant species and cultivars, such as leaf shape and root features, help alleviate numerous environmental issues.

“We are continually identifying new ‘super plants’ with unique qualities which when combined with other vegetation provide enhanced benefits while providing much needed habitats for wildlife.

“We’ve found for example that ivy wall-cover excels at cooling buildings and hawthorn and privet help ease intense summer rainfalls and reduce localised flooding.

“If planted in gardens and green spaces where these environmental issues are most prevalent we could make a big difference in mitigating against and adapting to climate change.”