Want to make every drop of rain in your garden count? We’ve got a hack just for you – it’s called a raingarden. Read on to get the lowdown on what they are and why you should install one.

A raingarden next to a footpath.
A raingarden next to a footpath. Photo: Photojo.

What is a raingarden?

A raingarden is a specially designed garden bed that collects water runoff from hard surfaces in your yard, like roofs and pavers, to better use rain by keeping it on site and filtering it before it moves on.

There are many different types of raingardens, such as above-ground planter boxes, in-ground gardens or even swales, and they all collect rainwater.

Who should install a raingarden?

If you’re the kind of person who forgets to water your plants and ends up with shrivelled stalks, you are a prime candidate to install a raingarden.

By collecting the rain that runs off your roof, driveway, and other hard surfaces, and directing it into a raingarden, you can keep those plants in your garden that you might otherwise forget to water looking lush.

It won’t cost you a fortune or take a lot of effort to maintain.

Are there other benefits of having a raingarden?

Yep. They’re an excellent way to help slow down and clean up rainwater – which picks up any pollutants it washes over, like dog poo, soaps, household cleaners and oil – before it runs off your property into local creeks, rivers, and the sea.

It does require the right selection of plants to do this, but aside from that tiny hurdle, they’re a very easy way to help play a role in keeping waterways clean for Adelaide’s native animals, like rakali and, one day, platypus.

A pipe feeding water into an in-ground raingarden.
A pipe feeding water into an in-ground raingarden. Photo: Melbourne Water.

How do I install a raingarden?

The first step is to work out what type of raingarden would suit your house and yard, and whether you would like to grow vegetables or native plants.

Different raingardens are suitable for different uses or locations. For example, an above-ground raingarden would be best located near a downpipe, and a below-ground raingarden is likely to collect more water if it’s near a driveway or patio.

Check out this video from our partner Water Sensitive SA for step-by-step instructions to install a raingarden to suit your home.

Make sure you employ a certified plumber to assess any impacts from modifying or diverting stormwater, and to actually make the modifications.

If you’re going to be doing any digging, we also recommend checking in with your local council to make sure you won’t strike gold, only to find it’s some kind of important pipe.

What plants do I need to use to clean rainwater?

Some plants are better than others at filtering out pollution. For your raingarden to be effective in cleaning stormwater (aka rain that has picked up pollutants), you’ll need to make sure at least 50% of your plants are nitrogen-fixing – sounds complex, but these are just plants that suck up nutrients.

There are lots of great native plant options you can use. Suitable favourites include common everlasting (Chrysocephalum apiculatum), karkalla (Carprobrotus rossii), silver banksia (Banksia marginata) and a black-anther flax lily (Dianella revoluta).

Some of the plants suitable for a raingarden.
From top left: common everlasting (Photo: Caro Taylor), karkalla (Photo: Sharn Lucas), black-anther flax lily, and silver banksia.

For a full list of plant options, check out this guide to raingarden plant species, or ask staff at State Flora or your local native nursery to recommend the best plants for you.

Do I need a specific type of raingarden to clean water?

If your main aim is slowing down the rate of water run-off and cleaning the water, you can use in-ground or planter box options.

Can I grow vegetables in a raingarden?

Yes! If you want to grow vegetables in your raingarden, an above-ground planter box with sub-irrigation is a great option.

This kind of planter box is designed to receive water through a pipe to a base reservoir, like a wicking bed. The plants then suck up the water through their roots as they need it.

This design reduces the evaporation that happens when water is just poured on top of the soil. It also stops your veggies getting drowned from a downpour.

Veggies like beetroot, tomatoes, onions, and greens particularly like raingardens.

Can I use mulch on my raingarden?

It’s not recommended. Mulch will likely wash away in a storm and can even clog up your system.

Similarly, avoid gravel, as it stops plants spreading and gives them heat stress.

I’ve set up my raingarden – what now?

Once your raingarden is set up, you’ll still have to do the odd thing to keep it happy, such as weeding, making sure water doesn’t erode the surface of the soil, and checking that all your plants are getting evenly watered.

Otherwise, just sit back and enjoy.

Discover more gardening tips

Want to make your yard a cool, green, and wild haven for yourself and the local wildlife? Explore our gardening hub for plant suggestions, after care tips, how to attract butterflies and native bees, and everything in between.

Alternatively, if you were here for the water cleaning – check out our tips for looking after waterways (of which, a raingarden is one of them).

Main image: In-ground raingarden (image courtesy of Melbourne Water).

This story is based on this Good Living article.

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