Wetland wonder

Use your grey water to turn an eyesore with boggy soil into a striking wetland.

Bright flowers, arching Cape restios and dramatic foliage are a far cry from what many of us picture when we hear the term “wetland”. Although the concept of wetland planting is a fairly recent development in a semi-arid country like South Africa, it is indeed possible. The good news is that both indigenous and exotic wetland and marginal plants are becoming easier to come by, making it possible to achieve plant combinations that you could only dream of before.

What exactly is a wetland? In the simplest terms, it’s an area covered with water for long enough periods of time to support plant communities that live in water or water-logged boggy soil. It also provides a habitat for fish and wildlife.

To the gardener’s eye, natural wetlands may look a bit dull, largely comprising bulrushes, reeds and other green plant material. However, a botanist would delight in finding water-tolerant plants with colourful blooms tucked among the greenery. It is these plants that garden landscapers in high rainfall countries have used for decades to create enchanting bog gardens. Such designer gardens typically consist of a pond with an adjacent bog, as well as an area of permanently moist soil that nevertheless drains well. The latter affords the right conditions for a greater selection of colourful plants known as marginal plants.

A botanist would delight in finding water-tolerant plants with colourful blooms tucked among the greenery.

Maximise your grey water

Many owners of smallholdings and country properties aren’t connected to a municipal sewerage system and have to make their own arrangements in this regard. They’re in a position to establish a wetland with the greatest of ease: simply position it where the grey water from baths, showers and washing machines exits the disposal piping system. Add masses of well-rotted compost to the area regularly, plant it, and watch a once-avoided muddy area become a wetland garden.

By selecting certain plants, you can purify your waste water before it leaves your property. Cleansing plants include the common reed ( Phragmites australis) and bulrush ( Typha species and Scirpus species) – but be aware that these are large plants. The smaller umbrella sedge ( Cyperus textilis) and Cape thatching reed ( Elegia tectorum) are also water purifiers.

Start a wetland from scratch

For practical reasons it is best to choose a low-lying area or a natural depression on your plot. An area with heavy clay soil that drains slowly may also be suitable. If, however, the root zone >

in such a spot becomes dry at times, you’ll need to make the area waterretentive, as described below. A wetland area next to an existing pond can also be created in this manner. 1 Lay out the shape of your wetland using a hosepipe. 2 Dig out the soil to a depth of 50cm to 70cm. Slope the sides gently to the deepest area. 3 Line the depression with a thick black plastic liner, after putting a layer of fine sand 2-3cm thick in the bottom to prevent the liner from being punctured by small stones. 4 Puncture the liner with pencil-sized holes in a few places about a third from the top to allow for slow drainage. 5 Fill the hole with a mixture of soil, masses of compost, and waterretaining granules. The latter two help to hold moisture in the soil during regional dry seasons. 6 Cover the edges of the plastic with soil or rocks to hold the liner in place and conceal it. 7 If it is feasible, attach rubber tubing to the end of a nearby drainpipe to channel rainwater from the roof into your pond and wetland. Also use berms and swales to direct rainwater run-off. 8 During your regional dry season, make sure that the root zone always remains moist, even if the topsoil appears dry at times.

Choosing plants

Wetland plantings can be enhanced by using both water-logged soil and the adjacent soil that is moist but well drained.

• Go vertical All gardens need vertical structure, and wetlands are no exception. Start with the tallest plants, placing them either in the centre of a large wetland or towards the back of a smaller wetland that will be viewed from one side. The taller papyrus, reeds, rushes and elephant ears are ideal.

• Fill the gaps Now fill the gaps with plants with contrasting foliage, such as river pumpkin, white arum lily and bloodroot next to grass-like plants, or delicately foliaged shrubs next to the bold-leaved colocasias.

• Colour accents Next, provide bright accents closer to the edge of the wetland, bearing in mind their height and spread. Orange River lily, African gladiolus, the river poker as well as bog irises and the cardinal flower are good options.

• Finishing touch Lastly, put in lowgrowing foliage plants and finish off with groundcovers.

• Marginal options Many plants will thrive in the permanently moist soil next to a wetland, provided that the soil drains well. These include some versatile plants that thrive in both situations. Try the following indigenous options to add colour or foliage contrast: Crinum species, Cyrtanthus species, crocosmia cultivars, pink marsh dissotis (Dissotis canescens), blue squill (Merwilla plumbea or Scilla natalensis), scarlet river lily, red-hot pokers, common buttercup (Ranunculus multifidus), bloodroot (Wachendorfia thyrsiflora), watsonias, river bells (Phygelius capensis) and scadoxus.

More than 50% of South Africa’s natural wetlands have been destroyed by developments.

This pond in a Highveld garden, designed to attract wildlife, features indigenous aquatic and wetland plants.

A boggy area can be converted into a charming garden feature. The indigenous plants are dwarf papyrus, arum lilies and Cape thatching reed.

This grey-water wetland in the Highveld was planted in October 2013. The difference is just four months is astounding.

Rainwater can be directed into a small area with a micro water feature and wetland plants.