Getting water-wise while the heat is on

Published Mar 7, 2014


Cape Town - As

the heatwave continues, gardens are wilting under the dry onslaught of high temperatures. With National Water Week (March 17 – 22) and World Water Day (March 20) around the corner, now is the time to take strategic measures to protect the investment in your garden.

Despite the superb rains in the Western Cape last year, water restrictions are never far away.

Spare a thought for residents of Ballito, KwaZulu-Natal, who received a surprise text message last week informing them that the excessive use of water is banned. With immediate effect, Ballito residents may not fill pools or water features, use hosepipes or turn on irrigation systems until further notice.

As local gardeners bask in the knowledge this has been a wet year, take time out to prepare and plan your garden for tough times ahead. Take a look at your garden. Can you do more to group plants with similar water needs in different water-use zones?

Water-wise efficiency can be achieved in every garden. Whatever the size of your garden, there are microclimates operating which make corners warm or cold; sheltered or more exposed; wet or dry. The key to success is to assess your microclimates. When buying plants, look for those marked as suitable for the microclimate zones in your garden.



A water-wise plant can be defined as one that can survive with a minimum of water. The deeper the roots of a plant, the deeper the water must sink to reach them.

Garden centres use a national rating to divide plants into low, medium and high water users.

l “One Drop” plants are those with low water needs. They include abelia, agapanthus, arctotis, buddleja, Carissa macrocarpa, euryops, felicia, gaura, gazania, lavender, marigold, Olea europeana subsp. africana, osteospermum, rosemary, Searsia lancea, Tecoma capensis, Tulbaghia violacea and vygies.

l “Two Drop” plants are those with medium water needs. They include argyranthemum, Barberton daisy, Celtis africana, coprosma, cuphea, day lily, dianthus, hibiscus, hydrangea, Mackaya bella, Phormium tenax, petunia and zinnia.

l “Three Drop” plants have higher water needs. They need to be zoned near the patio or entrance, where they can be well watered. These plants include aquilegia, azalea, camellia, clematis, tree fern, ferns, foxglove, fuchsia, gardenia, heuchera, hosta, Japanese maple, Lamium maculatum and white arum.


The right place:

Grow plants that need moisture on the south and east side of buildings, and drought-tolerant plants in north and west-facing areas. Use shelter from north-facing walls to grow plants that need protection from winter cold. Group plants that need the most water near the house, and in containers on the patio, for easy watering.

An enriched, well-drained soil will help with retention of water, giving the plant a greater moisture reserve and an ability to withstand drought. If a shallow basin is made around newly-planted trees and shrubs, and around vegetables such as tomatoes and squash, water will collect and slowly filter down.

Sprinklers can’t always reach small plants that grow in the shadow of larger plants. A hand-held hosepipe is often a better choice for watering, as it also affords the gardener the opportunity of checking the welfare of plants. Water tanks that collect rainwater off roofs, and “grey” water recycled from bath and laundry water, can be used on the garden.

A blanket of mulch 8-10cm thick helps keep soil cool, retains moisture, discourages germination of weeds, and insulates soil from temperature extremes. Organic mulches come in the form of compost, shredded bark, cocoa husks, peanut shells and pine needles that will break down in time and return nutrients to the soil. Bark nuggets are decorative and long lasting.

A fabric weed barrier that allows light, air and moisture to penetrate might not suppress all weeds but is more environmentally friendly than plastic. Use this fabric only in places where plantings are permanent.


The right plant:

The low, spreading growth habit of water-wise annuals alyssum, nierembergia, portulaca, nasturtiums and verbena are useful as edgings, in pots, on banks and between paving. There are also low-growing plants from the Mediterranean region with leathery, hairy or narrow leaves that are able to withstand wind, salt spray and drought, and that require minimal water.

Most well-known of these are artemisia, cistus, lavender, rosemary, santolina, sage and thyme.

Where grass is not growing well, consider paving the area, leaving occasional spaces for plants.

Paved areas retain heat, so hardy, heat-resistant plants are the answer. These include arctotis, felicia, festuca, gazania, lavender, rosemary, stachys, strelitzia and verbena.

Grow water-wise plants that grow naturally in your region or have adapted to local conditions.

With their striking form and narrow leaves, yucca, cordyline and phormium are useful in low-rain landscapes as accent plants among large rocks, in pebble or gravel mulch, and as a contrast with plants of rounded shape.

Silver and grey foliage plants can be used in many places in the garden. They can be used to add lightness when combined with dark foliage, give interest to a white garden and mix well with pastels. - KAY MONTGOMERY, Weekend Argus

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