Can planting reduce the impact of flooding?

Planting plays an important role in managing rainfall, helping us ‘slow it down, spread it out, and soak it in’. By this we mean:

• It helps water to filter into the ground, rather than sit on the surface
• It temporarily stores rainwater in leafy canopies
• It allows some water to evaporate from the plant before it even reaches the ground

What plants should I choose?

It’s always important to choose plants, trees and hedges that suit your soil and levels of sunlight, but there are some general rules you can follow:

According to the Royal Horticultural Society (RHS) plants with large, dense canopies, and rough and hairy leaves allow rainfall to be stored within the foliage. Examples include:

• Yew (Taxus baccata)
• Cotoneaster franchetii
• Western red cedar (Thuja plicata)

Also some plants offer the benefit of reducing rainfall runoff due to their higher rates of evapotranspiration (how water is consumed by a plant). Examples include:

• Forsythia ×  intermedia
• Hawthorn (Crataegus monogyna)
• Privet (Ligustrum species)

The RHS report ‘Improving the environmental resilience of UK gardens’ offers more detail on this.

What else can I do?

As well as choosing appropriate plants, trees and hedges you can also create sustainable drainage systems that help manage stormwater locally. Examples include:

• Rain gardens – a shallow area of ground which fills with rainwater and then drains.
• Bioswales – similar to a rain garden but directs the rainwater to elsewhere in the garden before it drains away
• Green roofs – to help hold rainwater

Where can I find out more? 

Visit the Royal Horticultural Society website for more information on planting and landscaping to reduce the impact of flooding.