Creating a Rain Garden might be one of the hottest landscape trends but what is all the fuss about? Morag from Cardigan based Celtic Sustainables volunteered with The Wildlife Trust of South and West Wales at the RHS Cardiff Flower show earlier this year to find out why.
The term “Rain Garden” has changed over the years. Technically it has always been just one aspect of the design of Sustainable Urban Drainage Systems (SuDS) and referred to a type of soft landscaping that slows the flow of rainwater via small planted “puddles” before it reaches the drain or gulleys. A Rain Garden now tends to encompass a whole range of garden design components including soft landscaping, green roofs, water butts, water features and ponds. Essentially anything that attenuates or slow downs rainwater to help prevent flooding either through increased infiltration into the ground, slowing the flow of water to a watercourse or drainage system or storing rainwater in the garden for use at a later date or within the home for non-potable purposes.
Rebecca Vincent from The Wildlife Trust of South and West Wales explains “Our rivers are under a huge amount of stress in the UK, with increased urbanisation changing the natural flow of water, leading to increased water pollution and flooding. By creating a rain garden you can improve your local area for wildlife. What ever the style, rain gardens all share a common goal; to capture water in a beautiful and wildlife-friendly way!”
The idea in general is that water is slowed down (attenuated) to such an extent that the peak flow into rivers is decreased so much that the area downstream doesn’t flood. If everyone in an area makes small changes, a significant amount of storm water could be temporarily stored and the scale of damage during a flood event dramatically reduced.
Rain Gardens can be adapted to any outdoor urban space, including concreted gardens and school yards. They should ideally be planted with a variety of wildlife-friendly plants which will look beautiful whilst also supporting pollinators such as Bumblebees and Butterflies. As with the Trust’s Garden at the Flower Show, they are often planted with native vegetation.
The Garden was certainly put to the test at the Show. It rained and rained! When comparing the water dripping from the Green Roof on the Shed to the marquee roof, I observed that there was that no rain was making it’s way from the sedum planted roof into the guttering during those April showers so it was working.
Next year the volunteers have requested the Trust create a “Sun” Garden in the hope that it will somehow influence the weather. Of course, Celtic Sustainables’ water butts will be perfect for that garden too!