SURVIVING THE FUTURE The often harsh and negative impact of the human footprint on nature can be seen everywhere. It is probably fair to say that not one corner of the globe remains untouched by humans in one way or another. However, each of us can make a difference and live sustainably, even if it is only through the plants that we grow in our own domestic gardens. Without making changes that will reduce our use of natural resources, such as using recycled (grey) water to irrigate plants, we might be in for a surprise in the not too distant future. Becoming enviro-wise is no longer an alternative lifestyle; it is an absolute necessity. All of us have to change our habits and our carbon footprints. Essentially, Mother Earth and her resources simply cannot sustain a heavy-handed way of life where we continue to produce non-biodegradable items in their millions, while environmentally friendly alternatives abound.
A young specimen of Ferocactus wislizenii is grown in a pot made from a discarded car tyre that was turned inside out and trimmed into a star shape.
Ferocactus wislizenii flowers. Design minimalism. The typical Karoo-style architecture of this dorpshuis in Cradock in the Eastern Cape (South Africa) is enhanced with the addition of Aloe ferox (on the left) and two specimens of quiver tree, Aloe dichotoma (on the right), in the narrow front garden.
Stem succulents from the Old and New Worlds: the stately baobab, Adansonia digitata, the world’s largest succulent (above), Parodia herteri from Uruguay (top right), and the cylindrical Cyphostemma uter from Angola (bottom right).
Gardening sustainability need not lack style. Imaginatively resurrecting an entire garden, or even part of a garden, by using bold colour splashes and sculptural forms becomes easy with succulents. The essence of eclectic savanna elegance from the Old World is here recreated with Aloe marlothii, whose flowers vary in colour from yellow through orange to red and are carried vertically on horizontal inflorescence branches.
Bringing an inorganic mulch of grey pebbles into the mix gives this private reading corner in a Phoenix, Arizona, garden fresh, modern appeal without detracting from the bold architecture of Agave americana that forms the focal point.
The appropriate use of colour schemes can make or break a garden. The optimistic rich yellow hues of Aloe inflorescences: the creeping Aloe commixta (left), shrubby Aloe striatula (centre) and Aloe maculata (right), all from South Africa, are perfectly offset against the dominating greens of their leafy rosettes, and the uniformly green surrounding foliage.
Some years ago, scores of medium-sized to large specimens of Aloe dichotoma (quiver tree) were rescued from being destroyed by mining operations and re-established in the Karoo Desert Garden. Today this is the largest man-made forest of quiver trees in the world.
The entrance to the Garden, with Aloe microstigma flowering in the foreground. The Karoo Desert National Botanical Garden, in Worcester in the Western Cape, is a vivacious jewel in the crown of the South African National Biodiversity Institute (SANBI). The Worcester-Robertson Karoo is a recognised centre of endemism, meaning that a large percentage of the local flora is restricted to this area. The Garden started life in 1921 at Whitehill, near Matjiesfontein, some 140 km to the northeast, in the much more arid Great Karoo, where it eked out a living for nearly a quarter of a century until a decision was made to move to the present location in 1945. Although it is not quite in the Karoo proper, the Karoo Desert Garden (as it is known) has a magnificent desert charm and splendour. The town of Worcester, in the Breede River Valley, at the foot of the magnificent Hex River Mountains, about 120 km from Cape Town, was established in 1820, the same year that British Settlers landed in Algoa Bay, about 600 km up the east coast (where the vegetation, known as valley thicket, is rich in succulents). Situated on a hillock overlooking the town, the Garden sports a mix of different planting styles that generate a relaxed, rural atmosphere. One of South Africa’s nine national botanical gardens, the Karoo Desert Garden specialises in plants from the dry regions of South Africa – there’s not an
exotic succulent to be found. With over 2500 different species in cultivation, the Garden qualifies as one of the richest succulent plant collections in the country, despite taking up just 11 hectares (27 acres) of the 140 hectare (466 acre) property. The Garden is filled with succulents of all shapes and sizes, but the visitor does not get a feeling of gardening claustrophobia at all, thanks to the mountainous backdrop, which exudes a physicality of prominence and grandeur. World-renowned collections of succulents have catapulted the Karoo Desert Garden into the international spotlight, affording it the status of ‘desert botanical destination supreme’. BLENDING IN One of the advantages of gardening with succulents is their ability to blend in and combine with other plants. They are evergreen, although their juices do ebb and flow throughout the year with the rising and falling of temperatures, varying day lengths and amount of rainfall. Their unique advantage among plants is the ability to accumulate life-sustaining moisture during the rainy season, or even from just the occasional downpour, and store it in their various organs to sustain them through dry periods. With succulents, it is easy to plan and construct a planting scheme for your garden that will remain pleasantly and comfortingly static throughout the changing seasons.
Various drought-tolerant plants, including cycads, aloes, pachypodiums and mesembs (vygies) planted together, make for interesting borders and beds. The robust, red-leaved ground cover in the middle ground is Aloe vanbalenii. (EF)
Aloe microstigma and an orange mesemb add splashes of early-summer colour to the Karoo Desert Garden. (EF)
In the heat of summer, Aloe microstigma leaves turn a striking shade of red. Most specimens of Aloe microstigma start their lives in the shade of the shrubs with which they cooccur. Worcester is situated on the fringes of the winter rainfall region. It gets very hot here in summer, but in the cooler months the desert-like climate
welcomes visitors with the promise of spirit-lifting bright, sunny days, and crisp, clear air. The Karoo Desert Garden has several magnificent assets, including a series of behind-the-scenes collections of various South African succulent plant genera and families, the best known of which are the Haworthia and mesemb (stone-plant) collections, which can be visited by appointment. The collection of Aloe dichotoma (quiver tree) must rate as one of the largest man-made forests anywhere in the world of this otherworldly, stately species. Located in the main garden, it is worth visiting. Throughout the cultivated garden, there are plenty of informative storyboards and interpretive signage. The storyboards are loaded with details that will help gardeners adapt the lessons learned from landscaping large, sprawling areas for implementation in small, urban spaces. The hardscaping, such as paths and low retaining drywalls, adds a feeling of pent-up energy, emphasising the important role that physical structures play in landscaping today. In addition to viewing the cultivated gardens, visitors can hike several day trails that crisscross the entire property. THE QUIVER TREE In years gone by, the hollowed out stems of Aloe dichotoma were used by the San people as quivers for their arrows. The species can be easily grown from seed, which germinates quite readily, but growing A. dichotoma successfully outdoors requires dry, generally arid, summer conditions. It may tolerate mild frost, but will not survive high amounts of summer rainfall. The large yellow flowers, carried on short inflorescence stalks, mainly appear from June to August, although some plants flower as early as March or as late as October in the Southern Hemisphere. In the photograph below, Aloe dichotoma and its smaller, shrubby, close relative, A. ramosissima, can be seen growing side by side. (EF)
MORE ABOUT TREE ALOES When it comes to architectural shapes, one particular tree aloe stands out: Aloe barberae. It has a clean, but rough, greyish brown trunk that branches high up, with small to medium-sized rosettes of dark green leaves perched at the tips of the branches. Although hardly grown for its floral colour display, the jellybean-shaped flowers are a delightful orange colour and carried in small, dense inflorescences. Fast-growing, Aloe barberae thrives in most mild to subtropical climates. In cooler regions, where the temperatures drop well below zero, it will do well if planted in a position where it is protected from frost. Aloe dichotoma, the quiver tree, has a decided preference for winter rainfall, although not much of that. The trunks of mature specimens are covered in slowly-peeling papery flakes, giving them a decorated appearance. Like A. barberae, the quiver tree also carries its leaf rosettes at the tips of thick, stubby branches, but its leaves tend to be more greyish green. In contrast to A. dichotoma, Aloe ramosissima is a shrub rather than a tree. It also has a distinct preference for fairly low winter rainfall, but is not as common in gardens as its larger cousin. The fat-bellied flowers of both A. dichotoma and A. ramosissima are cigar-shaped and a bright, butter-yellow colour. Compared with other tree aloes, the majestic, tall-growing Aloe pillansii is rarer in cultivation, and rather scarce in nature as well. A distinguishing feature of this species is that the inflorescences are borne lower down in the rosettes, and curve first downwards and then up.
Aloe ramosissima, which is related to the quiver tree, is a small, robust shrub with bright yellow flowers. The quiver tree’s oval-shaped yellow flowers are carried in dense inflores cences during the winter months.
Depending on where they come from, quiver trees can flower anytime from March to October. (OVER-)DOING IT PROPERLY! Dedicating a specific area in a garden to growing succulents represents a relaxed attitude when it comes to garden design. Succulents planted en masse make an inspiring decorative feature, and this approach will have an even greater impact if groups of succulents are planted together in dense clusters throughout the garden. Gardening with succulents is not hard work as, once established, species such as Aloe arborescens virtually look after themselves and do not require annual replanting. This species must rate as the ultimate aloe for
cultivation, as it grows and flowers easily in virtually any situation and any soil type. All it needs is bright sunlight and a well-drained substrate. Arguably the most commonly grown aloe, excluding Aloe vera, an agricultural crop, Aloe arborescens is a stalwart of numerous gardens.
The rugged rocky outcrops in the Karoo Desert Garden are perfect foil for soft-leaved crassulas, especially Crassula rupestris with its pink leaves, as well as for aloes, which occur in the natural vegetation alongside the shale trail. (EF)
This near-perfect specimen of Euphorbia ingens (naboom) thrives in the warm desert-like climate of Worcester. Although this is typically a savanna or bushveld succulent tree, it adapts well to a winter rainfall regime. (EF)
The form of the naboom with drooping branches is far more rare.
The stems of Euphorbia ingens often take on a silvery shimmer in bright sunlight.
The shrubby, tree-like euphorbia, Euphorbia tirucalli, has thin, leafless branches. The stems of this cultivar, known as ‘Sticks-on-fire’, turn bright red during times of environmental stress.
The blue-leaved Aloe glauca is perfectly offset against a green-wall backdrop of Portulacaria afra. Unlike most species of the genus, Aloe glauca flowers in early summer, not in midwinter.
The mouth of the flowers of Aloe glauca is typically slightly upturned. LESSONS FROM MINIMALISM Strong-lined and bold specimen plants can be very effectively accentuated by limiting the number of accompanying plants. Even though such co-plantings can be understated and intricate, the aim should be to emphasise the colour, shape, size, symmetry and presence of the main plant, not the clutter around it. Examine the plant in its position from all sides to ensure maximum impact.
The reds, pinks and oranges of the flowering candles of the stately Aloe ferox glow brightly in a thin winter sun in the Karoo Desert Garden. The spiky Carissa haematocarpa, a robust shrub, has small white flowers that are perfectly offset against the dark green foliage. This species is an ideal companion for succulents in general.
Even when not in flower, the rosettes of Aloe vanbalenii make a spectacular display of bright red. The species thrives in bright sunlight.
Inflorescence of Aloe vanbalenii.
The succulent daisy, Kleinia ficoides, has magnificent, blue-coloured leaves. The plants grow as rounded clusters consisting of a network of stems on which leaves are held erectly. Although the inflorescences are quite small, the fluffy seeds enhance the beauty of the plants.
It is for good reason that these three scrambling aloes – yellow-flowered Aloe tenuior, red-flowered Aloe tidmarshii and Aloe ciliaris – are called the gardener’s aloes. They flower freely for a large part of the year and the large, scrambling clumps they form can hide a multitude of gardening malpractices.
Poellnitzia rubriflora, sometimes known as Astroloba rubriflora, is a relative of aloes and haworthias. It ‘hides’ under shrubby nurse plants, becoming conspicuous once the crimson red, erectly borne flowers, which remain closed at the tips, are produced in summer. The growth form and general morphology of Astroloba smutsiana is similar to that of Poellnitzia rubriflora, but its flowers are much smaller and somewhat drab. The soup plate-shaped and -sized leaves of Kalanchoe thyrsiflora, a species from further north in the African savannas, are bright red, with an undertone of warmth lurking just below the surface. When densely planted, it works well as a ground cover.
Haworthia pumila often hides under the protection of nurse shrubs. The leaves are dotted with white pearly outgrowths. When specimens are exposed to bright sunlight, the leaves take on a striking orange hue. The distribution range of the miniature, aloe-like representatives of the genus Haworthia, which consists of around one hundred species, is restricted to southern Africa. Haworthia cymbiformis subsp. cymbiformis is an Eastern Cape cliff-dweller.
Different selections of Portulacaria afra, the pork bush or spekboom, come in variegated leaf colours: one has yellow leaves towards the tips of the branches; another has pale, almost white, leaves with green centres throughout. The leaf colour contrasts pleasantly with the purple stems. FACT BOX ADDRESS: Karoo Desert National Botanical Garden: Roux Road (off the N1), Worcester, Western Cape. CONTACT: Tel: +27 (0)23 347–0785; Fax: +27 (0)23 342–8719; email: [email protected] OPENING HOURS: Mon–Sun 07:00–19:00. Plant sales: Mon–Fri 07:00–13:00, 14:00–16:30. BEST TIME TO VISIT: Year-round. Spring (Aug–Nov) is best for vygie displays. COST: Entrance fee charged during High Season (1 August–31 October). ATTRACTIONS: Guided tours of indoor succulent collection by prior arrangement; fee applies. FACILITIES: Kiosk and bookshop open during office hours. Picnics permitted (fires prohibited). ACCESSIBILITY: Not all parts of the Gardens are wheelchair accessible; enquire beforehand. INFORMATION: http://www.sanbi.org/gardens/karoo-desert
A bed of barrel-shaped ferocactus plants and other cacti, backlit by the sun, show their red spines on the ribbed bodies to best effect. The yellow-variegated agave in the central foreground is a cultivar widely known as Agave ‘Cornelius’; it is possibly a selection of Agave americana. (EF)
A mixed planting of cacti and succulents in Obesa Gardens which, for lovers of these plants, could be considered a small piece of heaven. (EF) The climate of the Great Karoo cannot be described as gentle. In virtually every respect it is harsh: summer temperatures often exceed 40°C, while winters are cold, with overnight temperatures as low as -5°C being quite common. And rainfall is low, on average only about 350mm per year. Unsurprisingly, plants that grow naturally in the Karoo are often spiky, fat-bodied masters of survival. Those found in cultivation are, of necessity, similarly adapted. This is not the place to see verdant green lawns and beds of colourful pansies and petunias. Instead, Karoo vegetation is perfectly adapted to meet the challenges of South Africa’s arid interior: low-growing shrublets, often armed with spiky or leathery leaves, sparse drifts of yellowed, seemingly bone-dry grasses interspersed with rugged and, at times, leafless acacia trees, under a crystal-clear sky. And of course, inevitably, succulents of all shapes and sizes and from a variety of continents, apart from Africa, thrive in this climate. Obesa Gardens is situated in Graaff-Reinet in the Eastern Cape, with an extended garden just beyond the town boundary. This must-visit destination lies just beyond the Noorsveld, a vast stretch of arid country that is visually dominated by Euphorbia caerulescens, known as the noorsdoring (surly
thorn), and the widespread Aloe microstigma and Aloe ferox. The Garden was named for the increasingly rare and endangered Euphorbia obesa, a milkweed whose very restricted natural distribution range is about 15 km south of Graaff-Reinet. This fat-bodied species has the appearance of a miniature Xhosa hut. Graaff-Reinet, a town widely referred to as the ‘Jewel of the Karoo’, is surrounded by the Camdeboo National Park, whose most famous natural feature, the Valley of Desolation, teems with succulents. Even though the landscape here is dry, the thick drifts of Portulacaria afra (spekboom or pork bush), appear as bright green clumps throughout the year. NOT SO SLOW AFTER ALL There is a fallacy that gardening is a slow, tedious business. Not so with succulents. With these plants increasingly available in the horticultural trade, it is becoming easier to establish a garden that will mature quickly. These fat, hardy plants grow fast, and fully developed plants can easily be established in the spot where they are intended to grow. Succulents, earthy and humble, work anywhere.
The entrance to Obesa Gardens is announced on a signpost just beyond a typical Karoo-style house, where purple bougainvillea contrasts sharply with the whitewashed walls. Sidewalk paving slabs have been lifted in chessboard fashion next to the entrance and cacti and succulents established in their place.
The entrance to the Gardens also serves as the entrance to the nursery. (EF) Although Obesa Gardens is relatively young – it was established 35 years ago – many of the plants look as if they have been here forever. Being exposed to the region’s hot summers and cold winters has honed and shaped them, with only the strongest plants surviving the often harsh environment. The climate in this part of the Karoo is ideal for growing succulents, and species from all over the world thrive here. Magnificent specimens from the Old and New Worlds grow cheek by jowl in the Gardens, making it something of a challenge to negotiate the narrow paths, many created from clay roof tiles. Short tar poles, strung together with wire, are cleverly placed over irrigation furrows to form walkways. Perhaps the most visually pleasing groups of plants grown in Obesa are the columnar and barrel-shaped cacti: the columnar ones towering several metres into the sky, while the barrels are squat and cushion-like. The stems of these plants are fluted and ribbed and, almost invariably, armed with fierce spines. Apart from the cactus garden, Obesa also functions as a thriving nursery, selling a wide range of cacti and succulents from South Africa and elsewhere. The nursery offers plants for everyone, from those with not
much more than a windowsill to house a few miniature succulents to landscapers and horticulturalists who require medium, large and enormous specimens for instant gardens and arid landscapes. Together, the Obesa Gardens and its associated nursery comprise one of the largest privately owned cacti and succulent enterprises in the world, housing about 7000 plant species. As a result of the good growing conditions, many of the succulents in the densely crowded display beds can attain remarkable sizes, making this a perfect place to assess your options and decide on companion plants to cultivate in a waterwise garden. Within the Garden, palm trees and citrus trees pleasantly complement the stark outlines and thorniness of the agaves, aloes, cacti and other arid-adapted plants.
Aloe dichotoma (centre background), the quiver tree from South Africa’s arid, winter rainfall, western regions, grows happily in Obesa, behind a young specimen of Dracaena draco, the dragon tree from the Canary Islands. (EF)
With its attractive, bone-like leaf margins and spines, Agave titanota thrives in a calabash-style clay pot in Obesa Gardens.
A gravel path edged with Karoo rocks leads to a large, branched specimen of Beaucarnea recurvata, the ponytail palm. (EF)
A young specimen of Beaucarnea recurvata grown in a container made from a discarded car tyre that was turned inside out and painted.
Allaudia procera, from Madagascar, stretching its leafy trunks towards the intensely blue Karoo sky. When carrying inflorescences, the trunks appear club-shaped towards their tips. (EF) Symmetry in the arrangements of the leaves on the trunk of Allaudia procera. (EF)
The trunks of Aloe barberae cleverly double up as props for hanging baskets.