The top pollution-busting trees to plant
The UK needs to plant 150 billion trees to achieve carbon neutrality by 2050, according to the Committee on Climate Change, writes HANNAH STEPHENSON.
TV gardening expert, awardwinning wildlife author and RHS ambassador Kate Bradbury has curated a collection of 50 trees packed with information about appearance, care needs, carbon capturing ability and the wildlife they support in her new book, RHS The Tree In My Garden.
Here, Kate offers five of her favourite pollution-busting trees, some of which can often be grown as hedges to keep the pollution and traffic noise out – and welcome wildlife in.
Ginkgo (maidenhair tree)
These slowgrowing and relatively compact trees are perfect for small gardens, she says, thriving in full sun.
“It’s an ancient tree, dating back 270 million years, which has survived climate change and extinction previously. It has beautiful leaves which go yellow in autumn and it’s very tolerant of pollution so can grow in very urban areas. Neither a broad-leaf tree or a conifer, it’s like a fossil of former times.
“It grows to 10m over around 20 years and isn’t fussy about soil, you don’t have to prune it and because it’s so old, it doesn’t have any pests or diseases because all of the things that used to eat it didn’t survive.”
Crab apple
“You can get really small compact crab apples – you can grow some varieties such as ‘Evereste’ in large pots. ‘Aros’ is a new dwarf crab apple growing to a maximum height of 3m and has almost black foliage, dark pink flowers and red crab apples.” “The beautiful blossom is invaluable to pollinators” she notes, adding that any deciduous tree is good at busting pollution because the leaves absorb the pollution and then when they shed the leaves in autumn the pollution is removed from the air.
Hazel
This is such a versatile tree and could be grown as part of a hedge, or as a standard or as a shrub or small tree, says Kate. It grows quickly so will soon fill its space.
Trim hazel hedges in late winter, before growth starts in spring. Never let the soil around hazel dry out completely – water in very dry weather if there is a long, dry spell.
Explaining the added benefits of hedging trees of all kinds, Kate adds: “The point about hedges is that they are at the same height as the pollution so if you think about cars on a main road, if you have a really tall tree it’s not going to absorb the same level of pollution as, for example, a hedge. Because of its density the pollution is caught more on the leaves. Hedges are the most pollution-busting varieties.”
Hawthorn
On Hawthorn, she notes: “These can be grown as trees or hedges, and are quite small-leaved, so are pretty dense.”
They are also thorny, so will deter burglars, while pollinating insects love the flowers and birds enjoy the berries.
Yew
“This is a very good pollutionbusting tree with very small leaves, which gives you a greater density of surface area to absorb pollution,” says Kate.
“If you grow yew as a tree it can be enormous, but you can grow yew as a hedge.”
■ RHS The Tree In My Garden by Kate Bradbury is published by DK, priced £20.