Hedges are better than garden fences as wildlife refuges and flood barriers – that’s why I’m taking them to Chelsea Flower Show

Most people are familiar with the Royal Horticultural Society Chelsea Flower Show with inventive and inspiring garden design exhibitions featuring a wide range of plants. But the annual London show, which opens on Tuesday 21 May, also offers researchers like me the chance to present horticultural science to a wider audience.

This week I’m taking Urban Hedges to Chelsea to show the benefits of using mixed hedges all year round, and the potential of using humble hedges for environmental education.

Hedges are an critical and common feature of urban and suburban areas. Over 40% of the UK’s 23 million gardens are still have a hedge. They don’t take up much space, so they’re popular as roadside dividers and boundary markers for parks and playgrounds. Hedges are also relatively economical and simple to install and manage. And while fences provide privacy and boundaries, they lack the opulence environmental benefits offered by the hedges.

Hedges act as pollution barriers, provide habitat for wildlife, support pollinators during flowering, produce berries for birds to eat, retain rainfall and reduce the risk of flooding, and (to a lesser extent) reduce noise. As Royal Horticultural Society As a scientist at the RHS, I have noticed that more and more gardeners, space managers, landscape designers and architects, local councils, parents and schools want to find out what hedges can do and how they can be used to make better employ of green spaces.

As part of my last Project financed by Royal Commission of 1851.I tested whether a mix of evergreen and deciduous hedge species would be more beneficial than using just one species. Deciduous plants that shed their leaves in autumn and winter tend to provide greater benefits in the summer months when they have leaves. Evergreens – plants that retain their leaves all year round – provide benefits in winter when other plants lose their leaves.

For four seasons I tested how well different types of hedges captured rainfall, reduced runoff and minimised the risk of flooding. I found that introducing evergreens such as Thujaevergreen conifer, in a deciduous hedge, such as hawthorn, reduced rainfall runoff in autumn and winter. In the summer months, deciduous hedges were best at absorbing excess water from the soil, allowing the ground to store more rainwater before it became saturated.

The details are still being worked out, but the overall benefits of having security over having no security are clear.

Educational tool

My team and I worked with Year 10 students at Hoe Valley School in Woking, Surrey, to assess the effects of planting two mixed hedgerows near a busy road on the school grounds. The students measured changes in soil moisture, air pollution particle deposition on leaves and temperatures around the hedgerows.

Curious about how hedges could lend a hand children become more familiar with nature-based solutions such as hedges, we explored how this horticulture research project changed students’ perspectives on what plants can do for the environment, as well as their own willingness to get involved in creating – and maintaining – green spaces in their local area.

We found that students who had prior gardening experience outside of school had significantly stronger positive attitudes toward the environment than those who had not. But students without prior gardening experience had a more pronounced positive attitude change as a result of our engaging learning activities.

Thus, exposure to environmental science and horticulture played a role in shaping attitudes among newborn people. Engaging in horticulture and environmental science at school can be an critical way to improve children’s connection with nature.

For Chelsea and other projects, I have partnered with my colleagues at the RHS in campaign for school gardening AND national educational program nature park to bring our ideas, resources, results and experiences to thousands of schools across the country. By spreading the word further, we hope to encourage even more schools to get involved, employ hedges as a teaching tool and improve the quality of the environment on their school grounds.

While they may not be flashy, costly or fancy, hedges deserve a lot more attention. We hope our Chelsea exhibition will get people talking about the humble hedge and encourage more gardeners to employ them as garden borders, which have countless environmental benefits.

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