SHAPED BY SUFFERING The has produced some of the most enduring and successful garden plants in the world.

by Ernst van Jaarsveld, Kirstenbosch

ardens originated in the using mulches have helped very sensitive root system which when somewhat.) Other disturbances does not like any disturbance, as Ghumans started cultivating come from the activities of dogs and they originate in areas where they plants that provided nourishment, cats, and domestic animals as well did not have to adapt to trampling medicines, clothing and building as trampling from humans, or grazing disturbances. Some plants material. Gradually gardening for especially from children. however, grow easily in any garden, aesthetic appeal emerged and today To survive in a garden, plants and are able to tolerate human gardening is the most popular hobby have to be 'garden-fit'. Many plants handling, neglect and ill treatment worldwide. There are no fixed rules, (for exampl.e, species like better than others. 'Garden-fit' people grow what they like and ericas, proteas and buchus) have a plants that spring to mind are enjoy, and gardeners are always spekboom (Portulacaria afra) , ready for a new challenge. But in Pelargonium, hen-and-chickens general it is the plants from (Chlorophytum comosum), abusive backgrounds that have kerkei (Crassula portulacea), become the most enduring and kransaalwyn (Aloe arborescensJ, popular garden plants. and Plumbago. The secret of their success is their ability to Disturbing practices tolerate disturbances, which Gardening is very disturbing to naturally would be grazing or plants. Disturbances include the trampling animals, droughts, cultivation of soil, planting, trans­ frost or poor soil. This ability planting, pruning and trimming, equips them to withstand the adding compost and fertilizers, rigours of growing in a garden. creating ponds, paths and other So if you blame yourself for the structures, breaking these down, death of your erica, relax, it died and cutting and disturbing roots. for other reasons. Invasive plants from neighbouring territories have to be regularly Garden-fit plants from the weeded out, necessitating a Eastern Cape regular disturbance of the soil. In my series of articles* on ' The very act of cultivating the soil Above. The marsh rose Orothamnus zeyheri, gardening' (now consolidated admired by all but not suitable for the garden. into a book, Wonderful waterwise benefits the emergence of pioneer Top. The thicket vegetation of the Eastern Cape, plants - usually known to us as cradle of the world's most popular 'garden-fit' gardening), I emphasized how to weeds. (New gardening techniques plants. Photos: E. Van laarsveld. garden effectively with

16 Veld & Flora March 2001 indigenous plants adapted to a specific ecological in South . Obviously, a plant would prefer to grow in its own region, but there are some indigenous plants that thrive in gardens throughout the world. If a plant thrives in gardens within its ecological region I call it 'locally garden-fit', and if it thrives in each area, I give it a good 'overall garden-fitness' score. Most plants with a high 'overall garden­ fitness' score originate in the Eastern Cape, which can be conferred with the title of 'Cradle of the world's most adaptable garden plants'. Plants from this region have had a major horticultural impact on the world. On the annual Dutch garden and floral market at Alsmeer, plants are rated according to their sales (reflecting their popularity) and many South African plants are high up on the scale. Pelargonium cultivars have been rated for many years as the tops, and colourful pelargoniums grace the balconies of buildings and gardens in cities throughout northern hemisphere. Other popular houseplants from South African include the spider plant or hen-and-chickens Chlorophytum comosum, forest lily Clivia miniata and many of our herbaceous, succulent and bulbous plants. Plants from the Eastern Cape are easy to grow, adaptable, hybridize The world's most popular garden plant, the pelargonium, graces the streets of . easily and can take rough handling. It originated in the Eastern Cape. Photo: E. Van Jaarsveld. They are remarkably tolerant of disturbance, having evolved side by such as Carissa haematocarpa The plant breaks off but the stolons side with grazing animals. In their where only smaller grazers (the remain behind. Sansevieria leaf habitat, grazing and trampling is a leopard tortoise, dassies, bushpigs fragments will rapidly root when major driving force (just as fire is or porcupines) can reach them. left in the ground and form plantlets. the driving force for adaptations in Pregnant onions (Ornithogalum They are one of our most adaptable fynbos, and ). In longibracteatum) and the cliff fire garden plants. the fertile soils of the Eastern Cape, lily (Cyrtanthus montanus] have Most of these plants have a many plant species are highly loose bulblets that re-sprout after degree of succulence so that if they nutritious and in great demand for disturbance. Leopard tortoises are become detached from the mother grazing. This thicket vegetation used very fond of Ornithogalum, plant, they can survive on stored to carry dense populations of larger Crassula and Adromischus. The water and food. That is why they and smaller mammals (including hen-and-chickens, Chlorophytum transplant so easily and grow so domesticated animals). Evolutionary comosum, forms plantiets on a long happily when thrown on the responses to grazing pressure inflorescence, that rapidly root and rubbish heap! I have seen cycad resulted in thorns, bitter sap (a form dense mats. Plectranthus stems dumped on a rubbish heap chemical defence) or camouflage! madagascariensis and P verticil­ starting to re-sprout after a few Some plants even exploit this latus are also mat-forming and re­ years. Aloe arborescens, A. ferox, abuse. Many rely on disturbance in root rapidly after being trampled. A. africana, and many other aloes order to vegetatively reproduce. Mother-in-Iaw's tongue, Sansevieria can be chopped up and thrown in a The spekboom (Portulacaria afra) aethiopica has fibrous leathery corner and will even start flowering sacrifices its branches to grazing leaves that are browsed by rhinos. and put out new roots a year later, mammals, but when the branches The stem and subterranean stolons in spite of lying sideways. Similarly, are dropped they re-root quickly, are brittle, allowing the leaves break the spekboom (Por~ulacaria afra), forming new plants. Gasteria and off easily, leaving the stolons behind thicket spursage (Plectranthus Adromischus leaves are brittle and to re-sprout. (Gasteria and madagascariensis), ivy-leafed readily detach when grazed or Adromischus in contrast have brittle pelargonium (Pelargonium touched, but the leaves or fragments leaves that are adapted to browsing peltatuml, red pelargonium that fall rapidly re-sprout, often in by tortoises.) Have you tried to (P inquinans) and the zonal the protective arms of thorny plants uproot a Sansevieria by pulling it? pelargonium (P zonale) make good,

Veld Er Flora March 2001 17 Left. Pregnant onions, Ornithogalum longibracteatum, have brittle bulblets along the stem. When grazed by tortoises, bulblets fall to the ground and grow. Above. A leaf fragment of the ox tongue, Gasteria, that fell to the ground has rooted and formed many plantlets - one of the ways in which a plant exploits abuse and grazing. Opposite page, above left. Haworthias are popular tortoise food. Haworthia cymbijormis is stoloniferous and simply re-sprouts ifgrazed by the leopard tortoise. Below left. A young leopard tortoise, Testudo pardalis. Right. Rhinos graze the mother-in-Iaw's tongue, Sansevieria aethiopica. The leaves are firm and fibrous, but brittle at the base of the plant, so they break off at ground level, leaving the subterranean stolons behind. Photos: E. Van Jaarsveld. 'A botanical garden in this region is a must! ,

easy to grow garden subjects. baobab (Adansonia digitata). succulent . The only My collecting experience from the Many garden-fit plants are vegetation unique to the region is Eastern Cape corroborates this. relatively tolerant of insect pests. the thicket . You often find a Plants collected were just placed in Have you ever seen a spekboom or curious plant combination - a paper packets without any nursing, mother-in-Iaw's tongue (Sansevieria) Euphorbia next to a Podocarpus and after a few days brought back being eaten by caterpillars, aphids falcatus, or a tufted mesemb like the and potted: all of them perfectly or grasshoppers? I have grown rare endemic Orthopterum coegana surviving my abuse. various forms of spekboom for years next to an epiphytic orchid like Rainfall in the Eastern Cape is and they are the most insect-free of Polystachya pubescens. There is a unpredictable and can occur at any all succulent plants! They offer great range of soils, and plants are time of the year. Long droughts and themselves to larger animals but tolerant of a wide soil range, from flooding are fairly common occur­ deter insect grazers. Agapanthus, the very fertile valleys where the rences. The plants are tolerant of hen-and-ohickens, Ledebouria thickets occur to the mineral-poor drought but can cope with too socialis and Plectranthus madagas­ quartzitic sandstone soil . much water: conditions that often cariensis might have the odd Consequently, they can grow in occur in our garden where plants specialist pest, but on the whole, gardens with differing soil-types. are often under- or over-watered. they are insect-free, a quality that Lastly, Eastern Cape plants are These Eastern Cape plants can take makes them ideal for the garden. tolerant of competition, as they are it! (The Eastern Cape succulents are Some plants only perform in able to grow in dense plant commu­ the only non-local succulents that sunshine, others only in shade. nities, sharing their habitat with thrive at Kirstenbosch. They are Many Eastern Cape plants are many other plants. planted in the eastern flank of the tolerant of sun and shade. When conservatory exposed to the full elephant grazing removes their Why fynbos plants are not garden-fit blast of winter rainfall and yet they shade-cover they have to suddenly We all admire the marsh rose grow, flower and reproduce!) get used to a high light intensity Orothamnus and if it was easy to The Eastern Cape is situated until the branches grow back and cultivate we would all have it in our along the margin of the subtropics provide shade again. This is the garden! Why does an Erica die if we and its plants are tolerant of low reason why Agapanthus can just walk around it or cultivate the winter temperatures as well as tolerate shade. It flowers best in sun soil below it? Again the reason lies extreme heat: a range of 7-40 dc. but can be grown in shade as well. within their native habitat. Just as That is why pelargoniums are easily Many Plectranthus will also tolerate the fertile soils of the Eastern Cape grown in Europe, and also in hot full sun although they prefer shade. and all the factors discussed above dry climates. In contrast, 'Aarons The Eastern Cape is the only have produced plants with high rod' or wonder plant Tinospora region in where most overall garden fitness, the mineral fragosa of the bushveld is a great of the and vegetation regions poor soils of the fynbos produced survivor of disturbance, but heat merge - afro-temperate forest, Nama plants with a low food value that and summer rainfall are critical for Karoo, fynbos, grassland, thicket, did not attract grazing mammals. its survival. Another example is the savannah and fragments of Instead, fynbos plants have become

18 Veld & Flora March 2001 adapted to frequent fires, and this is other garden types (i.e. the , Some plants originating in the reason they make poor garden fynbos, strandveld, forest and Karoo grassland also have a fairly high subjects. However, fynbos plants regions). Think of the attractive overall garden fitness and are grown from lowland, strandveld and impala lily Adenium multiflorum: widely today. With a history of riverine regions perform better than it would certainly die if planted in adaptation to a combination of mountain fynbos plants, as again, poor soil and exposed to wet grazing, fire and frost, many of the they have adapted to disturbances winters and would need to be grown highveld bulbs and herbaceous other than fire. Think of the in a container and taken indoors plants are popular garden subjects. mesembs, fynbos bulbs and during winter. These include Kniphofia, Freylinia for example, and the ease Plants from the succulent and Agapanthus, Gladiolus, Scilla, with which they grow. Molerats regions are easily Rhodohypoxis and Osteospermum. playa vital role in the sandy soils of propagated and grown but do not the strandveld and coastal fynbos thrive in areas with a high rainfall. The best recipe regions and plants such as They die from fungal diseases and The Eastern Cape has the best recipe Bokbaaivygies Dorotheanthus, competition from other fast-growing for producing plants that can vetkousies Carpanthea, Trachyandra garden species. They have a high survive in gardens anywhere in the and many of the bulbs are adapted local garden-fitness but low overall world: a semi-arid climate, unpre­ to molerat predation. They are also garden-fitness and require dictable rainfall, disturbances from adapted to a winter rainfall climate, protection. We have grown Karoo trampling and grazing animals, and no not perform to their plants at Kirstenbosch with diffi­ variable soil and light conditions, optimum in summer rainfall condi­ culty in well-drained soil on the and mild to hot temperatures. We tions. Restios are fairly adaptable ­ Mathew's rockery. The cooler condi­ can safely predict that the chances more so than many other fynbos tions prevent many from flowering of finding other international horti­ species. and in the end they die. That is why cultural hits from the Eastern Cape Generally fynbos has low overall the Botanical Society Conservatory is greater than anywhere else in garden fitness. They are difficult to was built so that plants from all South Africa. The Eastern Cape flora cultivate and propagate, and cannot over South Africa can be grown in a should be protected as a valuable tolerate general garden disturbances. controlled climate. cradle of world garden and house Plants from the afro-temperate plants. A botanical garden in this Garden-fit plants elsewhere in and lowland forest regions have a region is a must! ® South Africa fairly high overall garden fitness. Bushveld plants are generally easy They have adapted to disturbances to grow in the bushveld. They need on the forest floor and can take • See Veld &' Flora 82(2) June 1996 through dry summers, cool night tempera­ rough handling. Plectranthus, forest to 85(3) September 1999. Many of these tures and wet winters, and they floor succulents, Dietes, Scadoxus, back issues are still available from the cannot tolerate frost and low Clivia, Dracaena and Rhoicissus are Publications Manager at the Botanical Society, Private Bag X10, Claremont, 7735. temperatures, factors that exclude other plants with a high overall Tel (021) 797 2090, fax (021) 797 2376, them from growing well in most garden fitness. e-mail [email protected].

Veld Er Flora March 2001 19