Planting with species that thrive on less than 500mm of winter rainfall a year is the new reality for landscaping in Cape Town.
The politicians may have done away with the Day Zero concept, but the realities of the water situation in the Western Cape remains dire.
Water restrictions and the price of potable water have encouraged a new landscaping reality. The foundation of this reality is based on landscaping with plants that thrive with less than 500mm of winter rainfall. And in our current era of climate change, coping with dramatically wet years – followed by dramatically dry years.
Highs and lows
With an average rainfall of 464mm per annum, South Africa remains a water scarce country. In years gone by, Cape Town’s average rainfall was 820mm per annum. In 2013 and 2014, Cape Town’s annual rainfall exceeded this average with two dramatically wet years.
The winds of change arrived in 2015. Over the past three years, the rainfall received in Cape Town has swung way below the average: 549mm in 2015, 634mm in 2016 and 499mm in 2017 – the driest year since observations began in 1921.
Against this backdrop, landscapers are practising the art of resilient landscaping. “We need green spaces in our cities”, says Norah de Wet, Chairperson of the South African Landscapers’ Institute (SALI). “Professional landscapers are at the forefront of securing the intrinsic value of properties across the Western Cape by refitting, rehabilitating, restoring and installing resilient landscapes”.
Planting for resilience
“Choosing plants that can thrive in a winter rainfall area with less that 500mm a year of rainfall is key to the concept of resilient landscaping in the Western Cape”, says Deon van Eeden from Vula Environmental Services. “Only with a sound knowledge of fynbos flora, can one succeed in designing water wise, ecologically sound, resilient landscapes for the winter rainfall area”, he adds.
What is fynbos?
Becoming acquainted with the rich flora of the fynbos biome is the key to reliant landscaping in the Western Cape.
What is fynbos? Fynbos is a collective term for plants from the higher winter rainfall regions in South Africa (which excludes the low winter rainfall Karoo region). ’Fynbos plants are a wonder of the natural world”, says fynbos botanist and horticulturist, Ernst van Jaarsveld.
“Not content merely to eke out an existence where the landscape is parched in summer and drenched in winter, where soils are nutrient-starved and where fires frequently rage, this unique vegetation is exuberant in its floral diversity. Nowhere else on earth are so many plant species – about 85 000 – crammed into such a small area”, he says.
Resilient fynbos plants
Van Jaarsveld spent decades working at Kirstenbosch National Botanical Gardens and is a world authority on plants that grow in the fynbos biome. As such, he is uniquely equipped to offer suggestions on plants that should be used in resilient landscapes in the fynbos biomes of the higher winter rainfall region.
In a series of features, published in South African Gardening magazine, van Jaarsveld offered these ideas – for shrubs, perennials, restios and succulents.
The protea family provides many suitable small trees and shrubs, such as the 3-4m tall tree pagoda (Mimetes fimbriifolius), 2m golden pagoda (M. chrysanthus), 2m king protea (Protea cynaroides), 6m forest sugarbush (P. mundii), 3m oleanderleaf protea (P. neriifolia), 3m waterlily sugarbush (P. punctata) and 3m common sugarbush (P. repens).
The pincushions are spectacular and include: 1,5m tall Leucospermum cordifolium, Overberg pincushion (L. oleifolium), 3m rocket pincushion (L. reflexum), and 1m ribbon pincushion (L. tottum). There are also many lovely Leucadendron species, such as 3m-tall dune conebush (Leucadendron coniferum), 4m gumleaf conebush (L. eucalyptifolium) and 2m common sunshine conebush (L. salignum).
The shrubby buchu family contains many highly aromatic plants, which are responsible for the pleasant aroma so characteristic of a fynbos garden. They include the feathery-foliaged confetti bush (Coleonema album, C. pulchellum, C. pulchrum), and buchus (Agathosma crenulata and A. ovata).
Many colourful shrubby ericas do well in gardens and attract sunbirds. These include red-flowered 0,8m fire heath (Erica cerinthoides), 1m-tall E. gilva and 1m-tall summer-flowering E. speciosa. Other attractive shrubs include 2m-tall September bush (Polygala myrtifolia), yellow-bloomed 1,6m Clanwilliam euryops (Euryops speciosissimus), and yellow-bloomed 2m-tall coulter bush (Hymenolepis parviflora syn. Athanasia parviflora).
The fynbos sages, blue-flowered sage (Salvia chamelaeagnea), brown-flowered beach sage (S. africana–caerulea) and red-bloomed S. thermara, are smaller shrubs with pleasantly aromatic leaves which flower during summer. Podalyria sericea is 1m tall and has striking silvery leaves and beautiful pink pea flowers during winter and spring.
For foliage effects, try grey-leafed slangbos (Stoebe cinerea and S. plumosa), and grey-foliaged helichrysum. H. petiolare and H. splendidum make good groundcovers. H. cymosum has silvery grey leaves and yellow flowers. Grey-foliaged Ursinia abrotanifolia makes an attractive groundcover.
For colour in a landscape, plant 50cm high Christmas-berry (Chironia baccifera) with pink flowers and red berries, blue-bloomed wild aster (Feliciaaethiopica), F. linifolia or F. amelloides, low-growing Gazania krebsiana with orange to red blooms and G. rigens, with silver foliage and yellow blooms. Scabiosa incisa has striking pink flowers which attract butterflies, Stachys linearis bears pink to purple flowers in summer, 50cm tall Cineraria saxifragabears yellow daisies from spring to autumn, low-growing Geranium incanumbears mauve flowers all year round. Many succulents, such as the low-growing Ruschia lineolata with its mauve spring flowers, also provide splashes of seasonal colour.
There are many lovely Pelargonium species for the garden. Try P. cucullatum with rich purple-pink blooms, pinky-mauve P. abrotanifolium, P. cordifoliumwith beautiful heart-shaped leaves and showy pink blooms. Don’t forget the aromatic pelargoniums, such as lemon-scented pelargonium (P. citronellum), P. crispum, P. denticulatum and P. radens.
The tufted reed-like restios are highly ornamental and are indispensable for creating a fynbos atmosphere. They can be planted individually as focal points or en masse for special effects. The striking 2m-tall fountain reed (Elegia capensis) is one of the most attractive.
Others include 2m-tall besemgoed (Calopsis paniculata), 1,5m thatching reed (Chondropetalum tectorum), 1,75m rustling reed (Elegia racemosa), 2m-tall besenriet (Ischyrolepis subverticillata), 2-3m Rhodocoma gigantea and 2m thatching reed (T. insignis and T. spicigerus). In smaller gardens, plant 50cm tall cushion restio (E. stipularis), 1m silver reed (Thamnochortus cinereus),and 40cm golden reed (Restio festuciformis).
There are many ornamental fynbos succulent species that grow well in a garden setting. Striking, large, shrubby succulents for focal points include krantz aloe (Aloe arborescens), fan aloe (A. plicatilis) and fynbos aloe (A. succotrina), which flower in winter. Smaller aloes include the erect A.commixta, the spreading A. gracilis var. decumbens and A. mitriformis. If you prefer pastel blooms, try the crassulas – white-flowered Crassula alba, cream-bloomed C. cymosa, white-flowered C. nudicaulis and pink-bloomed C. scabra.
Mesembryanthemums or vygies typically flower in spring. Ruschia maxima is a rounded shrub about 1m tall with large leaves and pink flowers – an excellent choice for dry fynbos gardens. Other colourful fynbos vygies include yellow-bloomed Lampranthus glaucus, white to purple L. multiseriatus, purple L. amoenus, yellow or white L. reptans, and apricot L. roseus.
The cultivars of the pig’s ear – Cotyledon orbiculata, the green-leafed C. o.‘Shireen’ and grey-leafed C. o. ‘Eric’, form an attractive contrast when grown together. Their large, tubular, reddish flowers are produced in summer and attract sunbirds. Also try yellow-bloomed Scopologena vereculata and white Senecio crassulaefolius.