Liesl van der Walt
of Water-wise Gardening
the natural rainfall patterns
Where do you live? Most of southern Africa falls into a summer
rainfall zone with cold, dry winters while the Western Cape has
a typical mediterranean climate with cool, wet winters and hot,
dry summers. Use the local climate to your advantage by using
indigenous plants that have adapted to your local rainfall. Also
do most of the planting in the beginning of the rainy season so
that the plants have time to establish themselves before the dry
season. To find out more about plants suitable for your area,
read the articles on Veld
Provide shelter from the wind and
Create different areas in the garden to enjoy, by planting trees
for shade and windbreaks for shelter.
Group plants according to their water
Plants have different water requirements. By planning your garden
carefully, you can group plants according to their water needs
and avoid wasting water on plants that do not need it. For example
group the special plants with high water demands close to the
house, entrance or living areas so that they are easy to water
regularly and can be enjoyed daily. The plants with low water
requirement usually also need less maintenance.
Improve the soil
Whatever the soil type (sand, clay or loam) the quality and water-holding
capacity can be improved by adding compost. This encourages earthworm
activity, which helps to improve the soil aeration and water penetration.
Compost also enriches the soil with nutrients. This promotes the
growth of healthy plants, which will require less water and be
more disease-resistant than plants that are underfed. Before planting
dig in large amounts of well-decomposed compost.
Much more mulch
Remember to spread a layer of mulch between the plants immediately
after planting. By covering the soil with a thick layer of mulch
the amount of water that evaporates is reduced, the soil kept
cool, water run-off and soil erosion reduced, and the growth of
weeds reduced. Different materials can be used as a mulch, such
as compost, bark, leaves, wood chips, straw or pine needles. These
organic mulches have the advantage that they add nutrient to the
soil as they break down, but therefore have to be replaced regularly.
Inorganic mulches like pebbles and stone chips are also effective.
Reduce your lawn
A lush green lawn during the dry months requires a lot of water
regularly. First replace the lawn in areas where it is not growing
well, such as shady areas or along footpaths. Then decide how
much lawn space you need for outdoor entertaining, children and
pets. Replace the excess lawn with hardy groundcovers, a water-wise
flowerbed or interesting paving.
Most people over-water their gardens. Watering depends on your
soil type, irrigation equipment, the weather and the type of plant.
To determine the soil type, simply squeeze some damp soil in your
hand and roll it into a sausage. Sandy soils will fall apart;
loamy soil will hold together but crumble easily, and clay soil
will mould into different shapes without breaking apart. With
sandy soils, water drains quickly beyond the reach of the plant
roots and these soil therefore require short, frequent watering.
Clay soil has a high water-holding capacity, so it is best to
give a deep watering, less often. Also remember the following:
- Never water while the wind is blowing and only early in the
morning or in the evening to reduce evaporation.
- Group plant with similar requirement together and adjust
watering according to their needs.
- Do not water automatically, first check whether the soil
- With trees and shrubs, rather water copiously less often
so that the roots are encouraged to grow deeper.
Grow water-wise plants
When choosing plants for your garden try to select from the indigenous
plants from your area/biome. But you may also be tempted to try
some plants from other parts of the world which have similar climates.
In the Western Cape, many beautiful plants from other mediterranean
areas such as rosemary, lavender, thyme, cyperus and myrtle grow
well with a minimum of water. But always
be careful to avoid exotic plants which have the potential to
invade natural areas in South Africa like hakea, Port Jackson,
lantana and black wattle.
There are many beautiful plants which are naturally drought resistant.
To grow in dry conditions plants have developed a number of adaptations.
They survive by storing water, reducing water loss through the
leaves or by going underground during the dry season. When choosing
plants for your garden, look for some of these features:
- Succulent plants, such as aloes, store water in their thick
stems, leaves or roots.
- Plants like ericas have small or needle like leaves to minimise
the surface area from which water is lost by evaporation.
- Many bulbous plants like the March lily (Amaryllis belladonna)
survive the dry season by going dormant and "ducking underground".
- Annuals like the Namaqualand daisies (Dimorphotheca pluvialis)
have adopted a similar strategy, by surviving in the form of
- Hairy leaves, a waxy leaf coating, or grey leaves also make
it easier for plants to retain water and reduce heat.