Water-wise Gardening

As time goes on and our climate changes, perhaps becoming warmer, conservation of water is becoming more and more important.

Our country has large areas that are arid or semi-arid and even in areas where there is a reasonable rainfall, we still have water shortages over many months and the threat of water restrictions is ever present.

For centuries, South Africans have emulated gardening styles of England, Europe and elsewhere. No matter how appealing an English Style garden may be, the South African climate does not allow for large expanses of green lawn and extensive herbaceous borders of water guzzling annuals and perennials bred for cooler climates. It is only quite recently that gardeners have looked at water-wise and indigenous planting, which will thrive without too much extra help, as a more sensible choice.

Here are some tips that will enable you to protect our precious resource by creating a more sustainable and water-wise garden:

  • Lawns need a lot of water, so it would make sense to reduce the amount of lawn. Assess how much lawn you need for relaxation, entertaining and children’s activities and rather replace the superfluous areas with water-wise shrubs, waterwise groundcovers, wild grass, decking or paving, as reduced lawn area will result in less water use. Areas of your lawn that experience heavy traffic, and therefore become compacted, ideally should be replaced by paving so that the run off water can be channelled into the garden. Pavers should ideally have gravel or pebbles in between as this allows water to soak into the ground instead of running off as is the case with solid concrete paving. Avoid cleaning paved areas with a hosepipe; rather brush it down with a garden broom. It is best if you keep the lawn to a simple shape so that you can irrigate without wasting water on surrounding areas. Try also to do away with individual plants that are dotted in the lawn.
  • The richer your soil is in humus, the better the soil is at absorbing and retaining water, reducing water runoff and protecting the valuable topsoil. If the soil structure is good, the presence of soil-borne creatures, such as earthworms, indicates a healthy fertile soil. To aid this process of creating good soil, mulching is an important aspect of waterwise gardening. Mulching describes the practice of covering the soil with a layer of organic or inorganic material.
  • Mulching reduces water evaporation from the soil by acting as a barrier that prevents the moisture in the soil from being transferred to the atmosphere and nutrients from being leached from the soil or washed away; it also keeps the roots cool. Mulches can consist of organic  material such as pine needles, bark chips, straw, nutshells and fallen leaves, grass cuttings or inorganic material such as chipped stone and pebbles.
  • Hydra zoning is the practice of grouping plants together with similar water requirements. Place plants that need regular watering, such as roses, in an area with other plants that need frequent watering. Plants that need less watering, for example once a month, can be placed in another area of the garden. To further reduce the need for water of sun-loving plants that need maximum sunlight, mulch well and add water retention granules and lots of organic matter to the soil. Hardy groundcovers could be planted between and under shrubs to prevent water loss through evaporation.
  • Drip irrigation is the most effective form of watering because it goes directly to the roots where it is most needed. There is no splashing or spraying, so the water does not evaporate or land up where it is not needed. Irrigation could be connected to rainwater collection tanks which when depleted revert to municipal water. It is best to alter the amount of time the irrigation system is on according to whether it is the dry or rainy season. If heavy rains have occurred, turn the irrigation off for a couple of days. Set the system to water the garden when evaporation is at its lowest, before 10 am and after 4 pm, and try to avoid watering when it is very windy. Check your irrigation system regularly to avoid losing water through leaks and inefficiency.
  • In areas where there is substantial wind it is advisable to create windbreaks, which reduce the flow of air over the soil and in turn reduces water evaporation. A windbreak in the garden could be any grouping of preferably large shrubs that reduce wind flow into the garden or divert the wind away from certain areas in the garden. Wooden screens or shade cloth could also act as a windbreak. A non-solid windbreak is best, as it will allow some wind through in a diffused manner and it will prevent wind turbulence directly behind the solid structure.
  • There is little more soothing than the sound of moving water. Having a water feature in your garden is not synonymous with water wastage. Reducing evaporation is the key to a water-wise water feature. The aim is to have a water feature of minimum size with maximum effect by reducing the size of the open pans of water. You could plant water plants that cover the surface area or cover with pebbles. Avoid extravagant high-pressure movement in fountains and waterfalls as this increases evaporation. Importantly, ensure that there are no leaks in the pond, pipes and connections.
  • When you are choosing your plants, certain characteristics are recognizable in plants that have adapted to survive on very little water. These are plants that have hairy leaves, small or needle like leaves, closing leaves, a waxy cuticle, grey foliage, fewer leaves, succulent foliage and those with strong and deep root systems. Many indigenous plants are water-wise.

TREES

  • Acacia caffra
  • Acacia galpinii
  • Aloe barberae
  • Celtis  Combretum
  • Cussonia (Kiepersol)
  • Dais  Erythrina (Coral tree)
  • Heteropyxis natalensis (Lavender tree)
  • Olea africana
  • Olea europaea
  • Peltophorum
  • Podocarpus henkelii (Yellow wood)
  • Rhus lancea  Rhus pendulina
  • Schotia

SHRUBS

  • Agave
  • Aloe arborescens
  • Aloe bainesii
  • Bauhinia galpinii
  • Bauhinia natalensis
  • Buddleja
  • Coprosma
  • Diospyros
  • Dombeya
  • Euphorbia
  • Freylinia
  • Kalanchoe
  • Laurus nobilis (Bay)
  • Leonotis leonora
  • Plumbago
  • Polygala
  • Rhaphiolepis
  • Rosemary
  • tecomaria capensis
  • Westringia

PERENNIALS AND GROUNDCOVERS

  • Beschorneria yuccoides
  • Bulbine
  • Carpobrotus (Hottentot fig)
  • Dietes
  • Dymondia margaretae
  • Echeveria
  • Echinacea purpurea
  • Gaura lindheimeri
  • Gazania hybrids
  • Lampranthus species
  • Pennisetum ‘Rubrum’
  • Phlomis (Jerusalem sage)
  • Polygonum capitatum
  • Sansevieria (mother-in-law’s tongue)
  • Scabiosa columbaria
  • Stachys byzantina
  • Tulbaghia
  • Verbena peruviana

ANNUALS

  • Dimorphotheca aurantiaca
  • Dorotheanthus bellidiformis
  • Gaillardia pulchella
  • Grielum humifusum
  • Lobularia maritime (Alyssum)
  • Nicotiana alata ‘Grandiflora’
  • Petunia
  • Tropaeolum majus (nasturtium)
  • Verbena hortensis