Easy and Efficient Rain Gardens

After so much wonderful rain in parts of SA, there couldn’t be a better time than now to invest in a rain garden. Creating one is simple and is all about location, soil, and plant selection. Follow our guide on how to grow a functioning rain garden to prevent flooding, curb water runoff, and play your part in reducing pollution.  

A swamp or sanctuary?

Besides adding stunning décor features to the landscape, rain gardens are super useful and easy to maintain. However, a rain garden is not a swamp and there are some important elements to understand when creating one. Have a look at these key differences:

Sip on this: By temporarily holding and filtering all incoming water, a rain garden diverts rainwater from directly entering a municipal stormwater system AND prevents polluted water from directly flowing into streams and rivers – amazing! Another win for the backyard eco-warrior! 

Location is key

The first factor to consider when planning your rain garden is where to dig your bed. When in an optimal location with appropriate plants, your rain garden will act like a sponge and natural filter that absorbs and collects all incoming water, cleans it, and then percolates it slowly into the surrounding soil. You can also grow multiple smaller rain collecting beds as there is no limit to the size or amount you can have in a space. Ideally, look for areas in the garden that:

• Are naturally lower-lying spaces (downhill, at the bottom of slopes, ditches). If your garden is flat, however, dig a trench to direct rainwater or install gutter/irrigation pipes and slabs to navigate water flow straight to the rain garden.
• Areas that receive full or partial sun.
• Near a runoff source would be ideal (downspouts, driveways, rooves, gutters).
• At least 3 metres away from a building (to avoid deteriorating foundations).
• At least 10 metres away from septic tanks.
• Take note of any possible underground electrical cables or pipes in the area and plan accordingly.

Top tip: Before digging up an area, test the soil for efficient drainage first. Dig a deep hole and fill it with water. Come back 24 hours later, after which all the water should be absorbed. If not, you may have to replace your chosen area with better drainage soil and sand, which you can purchase from your GCA Garden Centre.

Let the building begin

1. Decide on the design of the new bed and what shape would compliment the rest of the garden. Typically, ovals or kidney bean shapes work well, especially when the length of the bed is longer than the width, which promotes optimal and even water dispersion.
2. Dash down to your GCA Garden Centre for a good soil mix. We recommend using a mixture of 50% coarse sand, 25% compost and 25% topsoil to ensure optimal drainage.
3. While you’re there, ask your garden centre guide to show you all available indigenous plants that match the sun requirements of your chosen location. Local plants are an excellent choice are they are naturally adapted to our climate, require much less fertiliser, and have far-reaching root systems that help send water deeper into the soil.
4. When considering possible plants, go for:
   • A group of plants in the centre that can handle wet feet and saturated soil
   • An outer circle of plants that are more drought-hardy
5. Once at home with your dug out new rain garden, fill the excavated area with the soil mixture. Remember to leave enough space for the new plants, mulch and water. When excavating, you want to dig rather deep to ensure you get as much of the premixed drainage soil in there as possible.
6. Transplant your centre wet stunners, followed by the drought-hardy plants around them. Give your new garden a deep watering in the late afternoon.
7. The final step is mulch up! Check out this article that compares the different types of mulch to help you choose the best one for efficiency and personal style: (link to living mulch)
8. Maintain your water garden by frequently checking for any debris that may have built up as well as the entry passages and trenches/gutters/pipes. Keeping everything intact will allow as much water to be absorbed as possible. Feed your garden twice a year with an all-purpose fertiliser available at your garden centre.

Mulch can be topped up anytime you see exposed soil, which will ensure your plants remain cool during the summer and warm during winter. Planting your rain garden now will give plants an opportunity to settle in before the cold arrives. When the rain comes again, your smart garden will be ready for action! Enjoy all the biodiversity as an extra bonus, and remember to keep your birdbaths clean and collect seeds for our visitors.

Source: Life is a Garden