Why we need more trees in urban areas — and 10 native species to plant

Here is a list of native tree species well suited to urban planting

Silver birch and downy birch are both native species

In the sweltering heat that descended in recent weeks, I am especially aware of the cooling effect of urban trees. 

In the city, where tarmac and concrete prevail, heat builds up and even lingers late into the evening. In a phenomenon known as ‘urban heat islands’, soaring temperatures are amplified as heat is absorbed by hard surfaces and the density of buildings blocks the breeze. Street trees’ leafy canopies offer shade and act as natural air conditioners too, releasing moisture through transpiration. Protecting existing urban trees, increasing the canopy cover in parks and open areas, and planting new street trees are now a priority as climate change takes hold.

Boosting tree cover in urban areas has lots of other benefits too, all increasingly pertinent in an era of rapid heating and biodiversity loss. We all know that trees vastly improve air quality, filtering noxious pollutants produced by cars and trucks from the air that people breathe. 

Trees add colour, texture, sound and soothing movement to urban and suburban areas. Trees alert us to the incoming spring with blossom and bud burst; they fill out streetscapes with luscious greens through summer; set the scene for autumn as leaves turn russet and golden yellow; and give character to winter with the shape and texture of their branching forms.

And of course, as an ecologist, I’m especially enthusiastic about urban trees because they provide much needed habitat for wild creatures in an otherwise bleak environment. For any tree-planting, native species offer huge advantages over introduced, non-native species. From the mycorrhizal fungi in the soil, connecting root tips with access to nutrients and helping trees in times of drought, to symbiotic associations with all manner of organisms, native trees have evolved in tandem with the ecosystems in which they live. 

Strategies such as pollination and seed dispersal are dependent on a specific suite of wild associates. Native tree species typically host upwards of 100 different types of invertebrates, and as a rule of thumb, the diversity of dependent species living in native tree species far exceeds the diversity of non-native species.

Rowan trees are popular with blackbirds and thrush. Picture: Thinkstock/ PA

Caterpillars of various butterfly and moth species, for example, are particular to species, and in turn are crucial sustenance for nesting and fledgling birds, as well as helping sustain butterfly populations that are now plummeting. 

All manner of small flying insects are food for the swifts, swallows and house martins we so love to see in towns and cities, as well as all the songbirds we delight in hearing each dawn and dusk. Blue tit, chaffinch, robin, wren, blackbird, thrush, and dozens of other wild birds, as well as bats, are all dependent in trees.

With heat upon us and the adaptation plans of many local authorities advancing, I am offering here a list of 10 native tree species well suited to urban planting:

Silver birch and downy birch are both native species which grow tall, slender, wispy and light, with small, delicate, diamond-shaped leaves that don’t take too much light from housing or urban streetscapes. Birch bark has an especially appealing aesthetic and they are also wonderful for wildlife.

Wild crab apple trees were held in high esteem in ancient Ireland, ranked as one of the seven ‘Airig Fedo’ or ‘Nobles of the Wood’ in the Brehon Laws. Gorgeous spring blossom makes this a most appealing urban tree for humans and for wildlife. Native crab apple trees are especially suitable as street trees because they rarely grow taller than eight metres.

Rowan trees are well suited to gardens and city streets, with bright, white blossom in spring and characterful red and orange berries in autumn that are popular with blackbirds and thrush, among others. Autumn leaf colours are spectacular, and they also don’t grow too bulky or tall.

Holly has the appeal of retaining their green leaves year-round, providing great shelter for wildlife through the winter. Berries on the female trees are attractive and offer winter feed for birds.

Wild cherry trees are famous for their generous and life-affirming spring blossom. Their autumn leaves produce a stunning range of peach and yellow colours too.

Hawthorn is a sturdy and generous native tree. Flowers in May provide pollen and nectar for pollinators and through the summer, hawthorn sustains dozens of different species of moth and butterfly. Bright red haws ripen in autumn and are great for birds.

Hawthorn is a sturdy and generous native tree. Picture: iStock

Hazel grows as many long straight rods with smooth golden bark that shimmers in sunlight. Hazel supports a wealth of wildlife in its canopy and casts a gentle dappled shade with its big, soft round leaves.

Irish whitebeam is a small, elegant tree with stunning silvery leaf buds and cheering bright red autumn fruits. Irish whitebeam is an endemic tree, meaning that it exists exclusively in Ireland.

Willow trees come in many varieties. Furry catkins appear from February which supply pollen and nectar to other early emerging bumblebees and hoverflies.

Scots pine is one of three native evergreen tree species. They can add wonderful character to urban areas, though they grow very tall, so are only suitable in select locations.

Whatever the planting choice, preference for native species and diversity is key for resilience, as diseases and insect pests can proliferate where diversity is poor. 

Many local authorities are making strides with urban tree planting. In Cork, the city council adopted a new strategy in 2024 to more than double the city’s tree cover to 30%. It states that the average person “should be able to see three trees from their window” and admirably sets out steps to prioritise neighbourhoods with the lowest tree canopy cover. The aim for the next few years is to plant 4,000 trees per year across Cork city, adding to the existing 310,000 trees.

Waterford has compiled a comprehensive tree map that is expected to help protect existing trees and inform new tree planting throughout the city. Communities and the council have been working together to create new native woodlands with a diversity of native species in green spaces throughout Waterford.

In Dublin, city streets and parks are home to approximately 100,000 trees and the city council plans to increase tree canopy for the city across parks, existing public spaces and as street trees. Rather than being a game of numerical targets, the most significant consideration in any tree planting will be about providing resources for both people and wildlife, giving each tree the best chances of surviving into maturity.