A lot of us may not know that Hedges have an ultimate, natural ability to reduce noise, capture pollution, provide food/shelter for wildlife, and mitigate flooding.
Wanting to gain the right benefit from a plant depends on what's important to you, but reducing air pollution is amongst one of the most commonly wanted plant abilities - especially for those who live in a busy/urban area.
A plant is highly reliant on its leaf coverage when absorbing traffic and air pollution. This therefore means evergreen species are usually best, due to their year-round leave cover (which then ensures continual pollution reduction, year-round).
Generally, the faster growing evergreen plants are the most effective in a shorter space of time, but any evergreen which grows to a reasonable height will work well, too. As a matter of fact, modern research has found that evergreen hedging that has a dense and "hairy" nature, is particularly good at soaking up any toxins in heavy polluted areas.
Ideal species when looking for a plant to reduce surrounding air pollution:
Western Red Cedar (Thuja plicata 'Atrovirens')
The glossy, dark green foliage of Western Red Cedar is much bolder than other types of conifers, and is displayed in wonderful, striking sprays. The leaves give off a sweet, pineapple-like scent when crushed between your fingers, making the plant that much more enticing. Thuja will also produce little cones, but is most loved for its rich, dense leaves.
Western Red Cedar has proved to be the ideal hedge for any garden surrounded by heavy traffic, as well as country and suburban settings, due to the way it can effectively absorb pollution particles. Including this, the tall stature can make it the perfect background to any colourful and small plants, which just need an accompaniment to make them stand out from their surroundings.
Cherry Laurel (Prunus laurocerasus 'Rotundifolia')
Though mainly know for their rich and stunning green foliage, Cherry Laurel hedging also showcases intricate, creamy-white flowers during spring, which are then followed with festive-like, red berries during winter - making it an amazing, decorative addition to any size of garden. As the berries are seen as a great welcomed source of food, Cherry Laurel encourages many birds to your garden, as well as the lovely flowers providing an opportunity to attract bees.
Having such a dense and thick nature, Cherry Laurel is perfect for absorbing toxins in busy, heavy traffic sites.
Shrubby Honeysuckle (Lonicera Nitida)
Having such packed, tiny leaves on long stems makes the Shrubby Honeysuckle plant a very full and dense hedging species. Lonicera Nitida also has the ability to produce creamy-white flowers, which develop into purple-blue berries, but is most likely only to happen when you've had a good summer.
Though many do not recognise the name, Shrubby Honeysuckle is a very popular hedge, which will grow well in most aspects. Being such a hardy, full, bushy plant makes it ideal for helping reduce air pollution.
That all being said, being such a simple hedge to maintain, we highly recommend considering Shrubby Honeysuckle for any inexperienced gardener looking for something easy to grow.
Leylandii (Cupressocyparis x Leylandii)
Leylandii is a popular, elegant hedge which is a great addition to any garden particularly looking for privacy. Though mostly well-known for its very fast growth rate of around 70-90cm per annum, gardeners tend to love the evergreen, fragrant foliage on Leylandii, too, which provides rich and dense colours of green year-round.
The plant is perfect for pollution, wind, and noise reduction, as well as consistent privacy year-in, year-out. However, please consider that Leylandii will grow very tall, very quickly, so it's important to keep the hedge at a manageable height (so maintenance does not get too difficult). It is common for people to have Leylandii hedges at around 5-6ft tall, in which can be easily maintained.
Franchet Cotoneaster (Cotoneaster Franchetii)
Last but not least, Franchet Cotoneaster hedging is known for its evergreen, sage-coloured foliage, five-petalled, dusty pink-white flowers in May, and rich orange-red coloured berries during Autumn. All its attributes make Cotoneaster Franchetii the perfect hedging species for attracting wildlife (mostly birds), and their habitats, who love to feed on the delicious berries during winter.
This hedging species has also proven to be successful at reducing pollution in areas with heavy traffic, as they soak up roughly 20%, or more, of the toxins than other varieties of hedging. This is due to their evergreen, concentrated, hairy leaves.
People sometimes compare the Franchet Cotoneaster to Cotoneaster Lacteus, but the key difference between the two is that Cotoneaster Franchetii is a lot more upright and does not need a wall or fence to support it.