Lavender, marjoram and ivy have been revealed as the best air-cleaning plants to include on a living wall, according to a new study by the University of Surrey in the UK.
Researchers planted 10 different species on a 1.4 meter-high green wall beside a busy road to see which were most effective in capturing pollutants from the air. Plants help reduce pollution by catching particles on their leaves before rainfall safely washes them down to the ground. By using a mixture of species, the researches were able to see which leaf shapes and plant properties were most effective.
The study found that out of the 10 plant species tested, lavender, marjoram and ivy captured and washed away the most pollutants from the air.
Best living wall plants for cleaning the air
It's no surprise to plant experts that these three plants, which are often grown by home gardeners both indoors and outdoors, were the most effective at capturing pollutants.
'Ivy and marjoram are known for their air-purifying qualities, making them beneficial additions to indoor spaces,' says Autumn Hilliard-Knapp, houseplant expert from Perfect Plants.
In particular, ivies have been found filter out airborne toxins. 'This includes formaldehyde, mold spores and allergens,' says Autumn.
Julie Bawden Davis, plant expert at Healthy Houseplants, notes there is another way these plants help reduce pollution.
'They absorb pollutants into their foliage and those pollutants make their way to the plant roots where they are transformed into useable food for the plants,' she says. 'Ivy is especially good at purifying air, although marjoram also does a good job,' she adds.
Other plants used in the study included aromatic herbs like Breckland thyme and sage. Having a range of leaf shapes and textures has proven to be the best way to create a living wall for air purification.
'We think a good mixture of species will produce the most effective green walls,' says Mamatha Tomson, postgraduate researcher at the University of Surrey.
This news comes after another recent study from the University of Surrey which revealed yew (Taxus baccata) to be the best tree for reducing air pollution.
