Following the lead from water authorities from as far afield as Sydney and Las Vegas, Rand Water has launched a Three Drop (3D) water-wise zoning campaign for summer.
The primary aim of the campaign is to educate gardeners on how to zone their gardens according to the water needs of their plants, in readiness for tough times.
The pressure on Gauteng’s piped water supply is mounting. If urban population growth and development continue at current rates, the demand for piped water in the province is expected to exceed supply by 2013. The next phase of the Lesotho Highlands Water Transfer Scheme may bring relief only by 2020 at the earliest, so the period between 2013 and 2020 will be characterised by water shortages.
The 3D water-wise zoning concept encompasses planting and landscaping concepts. Ultimately the aim is for gardeners to learn the water needs of different plants and group them in zones in the garden.
Depending on their water needs, plants are divided into “one-drop” plants (with low water needs), “two-drop” plants (with medium water needs) and “three-drop” plants (with higher water needs).
From a landscaping perspective, three-drop plants should be planted near the patio or at high traffic entrance areas where they can be watered weekly. Two-drop plants should be grouped in a zone slightly further from the house in borders and flower beds. In a water-wise garden, most of the outer perimeter of the garden should include one-drop plants.
This is a 3D guide to plants:
What are one-drop plants?
They originate from regions with between 300mm and 500mm rainfall a year; once established, they do not need water except during very hot dry spells; they need water every six to eight weeks during the dry months. Succulents are one-drop plants and need no extra water.
One-drop plants that could be grouped together include:
* Trees: Acacia spp, tree aloe, Buddleja spp, wild olive, karee, bush willows, white stinkwood, Kei apple, coral tree, lavender tree, September bells.
* Shrubs: Abelia, carissa, confetti bush, euryops daisies, felicia, lavender, lion’s ear, rosemary, Plectranthus “Mona Lisa”, philodendrum, plumbago, Polygala spp, dwarf pomegranate, Indian hawthorn, strelitzia, Cape honeysuckle.
+ Perennials: Agapanthus, asparagus ferns, clivia, Cape thatching reed (Chondropetalum tectorum), wild iris, gaura, blue statice (Limonium perezzi), ivy-leafed pelargonium, Scabiosa africana, Tulbaghia violacea.
* Groundcovers: Creeping foxglove (Asystasia gangetica), arctotis, stalked bulbine, hen-and-chickens, erigeron daisy, gazania, Plectranthus spp, trailing osteospermum, Sutera spp, star jasmine, vygies.
* Climbers: Bougainvillea, Chinese jasmine, canary creeper, star jasmine.
* Bulbs: Fan-leaved boophane (Boophane disticha), Crinum spp, Ornithogalum thyrsoides.
* Annuals: Hollyhocks, Free State daisy (Arctotis venusta), allysum, cleome, cornflower, cosmos, gaillardia, gazania, sunflower, straw flower, linaria, nasturtium, portulaca, verbena, vinca.
What are two-drop plants?
They originate in regions with between 500mm and 750mm rainfall a year; once established, they don’t need water in summer, except during very hot, dry spells; water once a month in winter.
Group these two-drop plants together:
* Trees: Deciduous fruit trees, silver birch, leopard tree, oaks, flowering peach and plum,
* Shrubs: Marguerite daisies (Argyranthemum cvs), aucuba, buxus, coprosma, cordyline, cuphea, Cycas revoluta, Duranta cvs, Euonymus spp, Freylinia tropica, gardenia, hebe, hisbiscus, hydrangea, box honeysuckle (Lonicera nitida), forest bell (Mackaya bella), mahonia, nandina, pelargoniums, roses, Solanum rantonnetii, Viburnum species.
* Perennials: Alstroemaria, acanthus, Michaelmas daisies, shrimp plant (Beloperone guttata), Shasta daisy, crocosmia, diascia, dianthus, Echinacea purpurea, hellebores, day lilies, red hot pokers, penstemon, New Zealand flax, rudbeckia.
* Groundcovers: Carex, festuca, liriope, mondo grass, lamb’s ear, snow-in-summer (Cerastium tomentosum).
* Climbers: Carolina jasmine, Mexican blood trumpet, mandevilla, pandorea, golden shower (Pyrostegia venusta), climbing roses, black-eyed Susan (Thunbergia alata).
* Bulbs: Eucomis, cyrtanthus, nerine, scadoxus, veltheimia, scilla, summer-flowering arums.
* Annuals: Queen Anne’s lace, begonias, candytuft, Chrysanthemum multicaule, clarkia, celosia, dianthus, eschscholzia, gomphrena, marigolds, nicotiana, petunias, love-in-the-mist (Nigella damascena), red salvia (Salvia splendens), zinnia.
What are three-drop plants?
They originate in regions with between 1 000mm rainfall per year. Once established they need regular watering throughout the year. Group these three-drop plants together in the garden:
* Trees: Japanese maple (Acer palmatum), swamp cypress, flowering cherries, willows, magnolia.
* Shrubs: Azaleas, camellias, tree ferns, fuchsias, Cape fuchsia.
* Perennials: Japanese anemone, heuchera, hosta, white arums, Canna hybrids, perennial phlox.
* Groundcovers: Acorus, Ajuga spp., creeping Jenny (Lysimachia spp), Lamium spp, baby’s tears (Soleirolia soleirolii).
* Climbers: Clematis.
* Bulbs: Amaryllis, begonia, dahlia, gladiolus, berg lily, Lilium spp., and all winter flowering bulbs.
* Annuals: Amaranthus, aquilegia, delphinium, impatiens, lavatera, mimulus, forget-me-not, salpiglossis, foxglove, Salvia farinacea, silene, torenia and all winter flowering annuals. - Saturday Star
* Visit www.randwater.co.za or www.lifeisagarden.co.za