The British Royal Horticultural Society has released a science paper that shows that hedges can mitigate air pollution if they are planted with the right plant. And that plant turns out to one that’s pretty familiar, the humble “cotoneaster franchetti” or Franchets’ Cotoneaster. And here is how you say it: it is either “Cotton Easter”, or “Cot Tony Aster”. Both are used.
To improve the air and to improve human health it is twenty percent more effective than other cultivars in absorbing pollution. The head research scientist, Dr. Tijana Blanusa states:
“On major city roads with heavy traffic we’ve found that the species with more complex denser canopies, rough and hairy-leaves 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.”
The cotoneaster has hairy leaves that trap airborne particles and could mitigate some vehicle pollution by being planted near high occupancy roads.
Last December I wrote about nine year old Ella Adoo-Kissi-Debrah, who lived near the major South Circular Road in southeast London.She died in 2013 after many asthma attacks and seizures requiring hospitalization.
Law and environmental experts linked her death in a coroner’s report to air pollution, setting a precedent. The levels of nitrogen dioxide and particulate matter that Ella was exposed to were beyond the World Health Organization guidelines.
Sadly her mother said that had she known about the deleterious impact of pollution on her daughter’s health she would have moved. Children who are growing are particularly susceptible to “disease or dysfunctional growth”.
The biggest environmental risk in the United Kingdom has been identified as poor air quality. One in three people in the UK are impacted by air pollution.
The Royal Horticultural Society notes that only six percent of people in impacted areas are planting garden appropriate plants. The society recommends cotoneaster franchetii along busy roads as hedge materials, and pollinators, shrubs and trees everywhere else for diversity and wildlife. I have attached a list prepared by West Coast Seeds on the best pollinators for this area here.
Meanwhile the Royal Horticultural Society is examining ivy wall-cover to cool down building facades, and the use of hawthorn and privet hedges to slow strong rainfalls and associated flooding.
You can take a look at the video below produced by the World Economic Forum on the impacts of using the right plant in the right place to reduce air pollution. And by the way, the Cotoneaster plant is evergreen in our climate, hardy to zone five. It is a complete win-win in your garden. Or beside any highway.