Gardening in the Eastern Cape

East London Picture courtesy South Africa Tourism see their flickr pageEast London Picture courtesy South Africa Tourism see their flickr pageA good knowledge of the soil and climate type of the region you live in is half the battle won for gardeners, and especially helpful when selecting plants for your garden. Read more about gardening in the diversity of the Eastern Cape below.

The Eastern Cape Province is exceptionally topographically and climatologically diverse, with many distinct micro and macroclimates, created by the varied topography and the influence of the surrounding ocean currents. This can pose many problems for gardeners, unless you understand the subtle nuances of your particular region. 

The challenge of developing a garden in the Eastern Cape can be daunting for even the most resolute of gardeners. Often faced with impoverished soils, and at times severe drought, both amateur and knowledgeable gardeners often struggle to secure plant cover which is hardy and at the same time ornamental or edible.

Nqweba Dam Graaff Reinet. Picture courtesy South Africa Tourism see their flickr pageNqweba Dam Graaff Reinet. Picture courtesy South Africa Tourism see their flickr pageMuch of the Eastern Cape has been experiencing a severe drought since 2015, and while some parts are finally out of the drought, due to good rainfall throughout many regions of South Africa in the summer of 2022, dams on the western side of the province are still below average, and Nelson Mandela Bay Metro continues to face Day Zero.

The Eastern Cape is bordered by Western Cape to the west, the Northern Cape Province to the northwest, the Free State and Lesotho to the north, and KwaZulu-Natal to the northeast, and hugs the Indian Ocean. Because the region is influenced by both mid-latitude and tropical systems, it has a complex regional meteorology that has not been studied much, compared to other parts of South Africa.

The expansive landscape of the Eastern Cape is approximately 170 thousand km², stretching from warm deserted beaches with mountainous white dunes, to the cool green mountains inland. It extends from the mountains of the Drakensberg, with the southern spur of the Drakensberg rising to more than 2,700m in the north east, descending southward from the great interior plateau of the Highveld to form a relatively narrow coastal plain along the Indian Ocean, and along the border with Lesotho to the subtropical swamps of the Transkei coast.

In between the interior plateau and the coastline lie the dry semi-desert plains of the south-west, and the western central plateau is savannah bushveld, while the more eastern areas are extensive grasslands, and in the north east the vegetation is subtropical. In the transition zones of these diverse biomes the plants are a fascinating intermingling of the aromatic, succulent-rich Karoo types, with the lush subtropical vegetation of the north east, and the more temperate woods of the south.

Nieu-Bethesda Karoo Eastern Cape. Picture courtesy South Africa Tourism see their flickr pageNieu-Bethesda Karoo Eastern Cape. Picture courtesy South Africa Tourism see their flickr pageThe north and western areas of the high plains of the Plateau and great Karoo generally have little water, resulting in the semi-arid conditions that characterize them.  Graaff Reinet, which is in the Karoo Heartland experiences long hot summer months and moderate winters.

On the other hand, up towards the Free State, in towns like Lady Grey and Aliwal North, the significant rise in altitude results in much lower temperatures, and in the mountainous regions between Molteno and Rhodes it can become very cold in winter, with heavy snowfalls occurring at times. These are great examples of the great variances in climate of the Eastern Cape, where towns just a few hundred kilometres from the swelter of other areas, experience conditions favoured more by skiers than sunbathers!

If you travel inland from the coast you will clearly see how the great escarpment divides the coastal regions from the northern interior plateau. The escarpment is also responsible for precipitation production through orographic lift within the Eastern Cape and adjacent KwaZulu-Natal. Orographic lift occurs when an air mass is forced from a low elevation to a higher elevation as it moves over rising terrain.  As the air mass gains altitude it does so without the loss or gain of heat (adiabatically) which can raise the relative humidity to 100% and create clouds, and under the right conditions, rainfall.

While the northern areas generally have hotter days and colder nights, to the south, the climate is quite different with few fluctuations in temperature and higher rainfall. Southwest of the Great Fish River, the topography is characterized by east-west-trending mountain ranges and valleys, and east of the Great Fish River, including the lower valley of the Great Kei River, perennial streams have carved deep valleys on their way down to the ocean, and as they wend their way down from the mountains they provide sufficient water to support a wonderful variety of wetland fauna and flora. 

The coast of the Eastern Cape is approximately 800km long and is highly diverse, harbouring a great variety of life. It is characterised by a rocky shoreline interspersed with bays, sandy beaches, dunes, rivers, and estuaries. The most prominent oceanographic feature of the region is the Agulhas Current that carries warm tropical water south-westwards past the south coast of South Africa.

Sunrise over the Umzimvubu River Port St Johns. Picture courtesy garethphoto see flickr PageSunrise over the Umzimvubu River Port St Johns. Picture courtesy garethphoto see flickr PageThe Eastern Cape is drained by four major rivers, namely the Mzimvubu, Great Kei, Great Fish and the Gamtoos. Other major rivers include the Mbashe and Sundays Rivers.  At least 139 estuaries have been categorised along the Eastern Cape coast, more than half of all the estuaries in South Africa. Some of the larger estuaries include those at the mouths of the Kromme, Gamtoos, Swartkops, Sundays, Bushmans, Great Fish, Keiskamma, Buffalo, Great Kei, Mbashe, Mtata, Mzimvubu, Msikaba and Mtamvuna Rivers.

The climate of the Eastern Cape is characterized by high spatial and seasonal rainfall variability, and rain producing systems include orographic forcing, frontal activity, convective action and tropical storms. The coast near Port Elizabeth is relatively dry, as is the western interior which forms part of the Karoo semi-desert region, but otherwise the coastal regions are much wetter, as are the north eastern inland regions near the Drakensberg and Maluti mountains (Lesotho).

Not only does the climate vary according to proximity to the ocean, but also in a west-east direction, getting progressively wetter the more eastwards you go. The coastal zones experience very moderate summer and winter temperatures, and the transition from the climate of the Western Cape to KwaZulu-Natal is especially noticeable along the coastline, as the climate slowly transitions from Mediterranean and temperate oceanic without a dry season, to humid subtropical with summer rainfall, and the further north you go, and the closer you get to KwaZulu-Natal, the more the heat and humidity increases. The Eastern Cape therefore incorporates aspects of both winter and summer seasonal rainfall. Mean annual precipitation varies considerably across the Province from 300mm per annum in the west to 1,000mm per annum in the east.

Winds and alternating cold and warm fronts also affect the climate throughout the region, alternating with the cold westerly winds, which may drop maximum temperatures to as low as 10 to 15°C, and hot berg winds from the interior north or north west which rapidly raise temperatures to 20 to 25°C in the winter, and to over 35°C in the summer. Winds generally have a cooling or drying effect so that humidity levels are not extremely high, except along the northern parts of the coast.

On the whole the weather is perfect for tourists in the Eastern Cape, rarely reaching extremes, except perhaps in the height of the Karoo summer. The changes depend on how much you move across the province’s expanse, and in and out of different climatological zones.

Mthatha Picture courtesy South Africa Tourism see their flickr pageMthatha Picture courtesy South Africa Tourism see their flickr pageThe Köppen-Geiger Climate Classification System

The Köppen-Geiger climate classification system is one of the most commonly used systems in the world today. It is used to denote different climate regions on Earth based on local vegetation, and classifies the world into five climate zones based on criteria like temperature, which allows for different vegetation growth. Vegetation and climate are intricately linked, and the vegetation that grows in a region is dependent on both the temperature and precipitation there, which are two key factors of climate. Many other criteria are included, but generally, areas with more rainfall and higher temperatures contain more forests while regions with less rainfall tend to be deserts.

Köppen published his first scheme in 1900 and a revised version in 1918, but he continued to revise his system of classification until his death in 1940. Subsequent climatologists, including Rudolf Geiger, updated versions of this map, which often include Geiger’s name as well. A recent revision to this map was published in 2018. Köppen’s maps are still used by scientists and climatologists to this day.

Two good sources to look at if you are interested in pursuing this subject further are: brittanica.com and mindat.org; and for the latest map visit researchgate.net

I have spent a lot of time seeking out the Köppen-Geiger classifications of various regions of the Eastern Cape and found it fascinating, but also quite confusing at times, with one source stating a city or town was (Cfa) and another stating that the same place was (Cfb) Nevertheless, this research did give me greater insight into the climate types of the Eastern Cape, and although some may vary somewhat, the basic principles still apply.

I believe this summary may prove very helpful to gardeners in the Eastern Cape, and you may even decide to do your own research on the Köppen-Geiger climate classification for your region. Links I used for my research include: weatherbase.com; and climate-data.org.  And if you are into detailed maps you have to visit maphill.com.

The Köppen-Geiger climate classification system for cities and towns of the Eastern Cape

Komani and Mthatha are excellent examples to begin with as they show how the various climate types and plant biomes of the Eastern Cape merge with one another. For this reason they have been classified under several Köppen-Geiger climate types. Many sources will list these places under only one type, but if you dig a bit you will find that this may not be correct. For this reason I encourage you to do your own research, as mine may also not be entirely correct.

Mthatha (Umtata)

Mthatha lies at an elevation of 698 metres, about 250 kilometres north of East London, and was founded in 1883, along the banks of the Mthatha River, or “The Taker River,” so named because of its habit of producing destructive flooding in the area.

Mthatha is a great city to start with concerning the Köppen-Geiger system, as it merges with four climate types, and is an excellent example of how the regions and biomes of the Eastern Cape merge with one another. It has a warm oceanic climate (Köppen climate classification: Cfb) closely bordering on a humid subtropical climate (Köppen climate classification: Cfa), and both cold and hot semi-arid climates (Köppen climate classification: BSh & BSk). The average annual temperature in Mthatha is 16.6 °C, with an annual rainfall of 1,044mm. Other sources classify it only as (Cfb)?

Komani (Queenstown)

Komani is a town roughly halfway between the smaller towns of Cathcart and Sterkstroom, and close enough to the Wild Coast and Karoo Heartland to make it a favoured stopover for travellers. It is the commercial centre of a rather prosperous farming community, and the town is known for its roses. It lies at the foot of the Hangklip Mountain, on the Komani River which forms part of the Great Kei system of rivers, and has a refreshing climate and plentiful water supply from the surrounding rugged mountains, where the Bongola Dam is situated to supply the town with water.

Queenstown has a cold semi-arid climate (Köppen climate classification: BSk), that borders on a subtropical highland climate (Köppen climate classification: Cfb), and a humid subtropical climate (Köppen climate classification: Cfa). However some sources list it only as (Cfb)?

In Queenstown it is mostly clear year round, the summers are warm, and although the winters are short, they are cold, dry, and windy. The average annual temperature is 15.5 °C with an annual rainfall of 669mm. Over the course of the year, the temperature typically varies from -0°C to 28°C and is rarely below -1°C or above 32°C.

An ocean or maritime mild winter climate (Köppen Climate Classification: Cfb)

Temperate oceanic climates, also known as "marine mild winter climates are found in both hemispheres, in both temperate and subtropical areas, at latitudes around 35° and 60°, and at low altitudes between Mediterranean, humid continental, and subarctic climates. Oceanic climates can be found in Western Europe, parts of central and Southern Africa, North America, South America, parts of Asia, and as well as parts of Australia and New Zealand.

Cfb zones are rare in Africa, and the only noteworthy area of Maritime Climate type Cfb, at or near sea-level in Africa, is in the Garden Route region of the Western Cape, extending up the coastline from Mossel Bay to Plettenberg Bay. Additional pockets of this climate type are also found inland of the Eastern Cape and KwaZulu-Natal coastlines.

Generally they feature mild summers (relative to their latitude) and cool but not cold winters, with a relatively narrow annual temperature range and few extremes of temperature. In addition to moderate temperatures, one of the characteristics of this climate type is year round rainfall with no pronounced rainy season, but slightly more rain in autumn and spring.

Loerie

Loerie is a town in the Sarah Baartman District Municipality in the Eastern Cape, about 25km north-east of Jeffrey’s Bay, and 11 km north-north-west of the mouth of the Gamtoos River is classified as Cfb climate type by Köppen and Geiger. It is warm and temperate with lots of rain even in the driest month. The average annual temperature is 17.8 °C, and annual rainfall here is around 533mm.

Kariega (Uitenhage)

Kariega is located 38km north-west of Gqeberhaa (Port Elizabeth) and 45km from the Addo Elephant National Park. It is fondly referred to as the “Garden Town” due to its many scenic parks and a climate that allows flowers to flourish naturally, with aloes covering the countryside, and the towns’ official flower, the Strelitzia, blooming just about everywhere.  

Uitenhage has short and warm summers, and the winters are cool and windy; and it is mostly clear year round. It has rainfall throughout the year, with an average annual precipitation of 452.1mm. The month with the most precipitation on average is October with 53.3mm, and the month with the least precipitation on average is June with an average of 22.9mm. The average temperature for the year in Uitenhage is 16.7°C. The warmest month, on average, is January with an average temperature of 21.7°C. The coolest month on average is June, with an average of 13.9°C.

Once again, one source will classify Kariega as (Cfb); while however will classify it as BSh.

Grahamstown

Grahamstown lies on the wooded slopes of the Suur Mountains near the source of the Kowie River, and because it lies at the intersection of four very different climatic zones, its weather is often unpredictable, especially in winter when it can get quite chilly. Along with towns like Alicedale, Sidbury, Riebeeck East, Hogsback and Alice, they form part of one of the most diverse ecological regions in South Africa, with thousands of hectares devoted to nature and game conservation.

The climate is warm and temperate, with significant rainfall, even in the driest month.  This location is classified as (Cfb) by Köppen and Geiger. The average annual temperature is 16.6°C and about 590mm of precipitation falls annually.

Somerset East

Somerset East is a small town with peaceful streets lined oak trees, white-washed settler cottages, and heritage roses; all lying in the benign shadow of the iconic Boschberg Mountain. This beautiful mountain is decked with waterfalls, pristine streams; and forests of Yellowwood, Wild Olive and Cape Chestnut, among the eighty plus other indigenous tree species which grow on the slopes, and some of the flora is endemic to the area. It lies on The Blue Crane Route which meanders along the R63 from Pearston, via Somerset East to Cookhouse, and was created as part of an alliance of farms on the route to save the Blue Crane from extinction. 

The countryside around the town is quite varied with impressive mountains, rich farmland, forest and open Karoo veld, all within a short drive of the town. It is classified as climate type (Cfb), with an average temperature of 15.4°C, and an annual precipitation of 620mm.

Fort Beaufort

Fort Beaufort rests on the banks of the Kat River, at the confluence of the Kat and Brak rivers, between the Keiskamma and Great Fish Rivers, and is surrounded by the majestic Katberg and Amatola mountain ranges, close to its neighbours - Hogsback, Grahamstown and East London. This little historical town dates back to 1822 and its fertile land is known for yielding delicious fruit crops, and is the centre of a prosperous citrus farming area. Its land is enriched with diverse plant species native to the Western and Eastern Cape regions. In the picturesque valley of Fort Beaufort lie semi-desert landscapes populated by a variety of fynbos, as well as deep, lush ravines filled with rivers and waterfalls, and forests overflowing with ferns and looming Liana treetops.

Fort Fordyce Nature Reserve is just 25 kilometres from Fort Beaufort, between the town and Adelaide, and has as its main purpose the conservation and protection of the biodiversity of the area, specifically the scarce Dohne sourveld, and the surrounding Afro-montane forests of the valley. Sourveld comes from the Afrikaans word “suur” and is a type of grazing characterized by long coarse grass.

Fort Beaufort is classified as a (Cfb) climate which is characterized by equable climates with few extremes of temperature and ample precipitation in all months. Its average temperature for the year is 18°C, with an annual rainfall of 558.8mm. The warmest month is January with an average temperature of 22.6°C, and the coolest month on average is June, with temperature of 13°C

Qonce (King William's Town)

Qonce was founded as a missionary station in 1826 along the banks of the upper reaches of the Buffalo River, and the city is about 60km northwest of East London. It lies 389m above sea level at the foot of the Amathole Mountains, an area known for its agriculture. The town is worth visiting for its natural beauty and streets lined with Jacaranda trees. Its botanical garden also features five separate conservatories.

King William's Town's climate is classified as (Cfb) by Köppen and Geiger and is warm and temperate, with significant rainfall during the year, even in the driest month; and the annual temperature here averages 17.2 °C and the average rainfall is 722mm annually.

Mount Pleasant

Mount Pleasant is a leafy suburb of Port Elizabeth and is classified as (Cfb) by Köppen and Geiger, although Port Elizabeth is classified as (Cfa). The climate is warm and temperate in Mount Pleasant, with significant rainfall, even in the driest month. The average annual temperature is 16.6 °C and the annual rainfall here is about 1,044mm.

Maletswai (Aliwal North)

Maletswai is a town on the banks of the Orange River, in the northernmost part of the Eastern Cape. The settlement of the area and its development into a town is most likely connected to the presence of good water, thermal springs, and a good fording place across the Orange River, just below its confluence with the Kraai River. The principal attractions are two hot mineral springs, both of which have extremely high concentrations of minerals and gases.

Its climate is classified as (Cfb) as it is warm and temperate. The summers are warm; the winters are short, cold, and dry; and it is mostly clear year round.  Precipitation is significant even during the driest month. The precipitation is 696mm per year, and the average annual temperature is 15.7°C.

Lady Grey

Lady Grey is a rural village in the North of the Eastern Cape near the border with Lesotho. The area, which also includes towns like Barkly East, Elliot and Aliwal North, is surrounded by many scenic Passes, and Lady grey is tucked away in a valley below the awesome Witteberg mountain range, 54km due east of Aliwal North. The area is rich in sandstone fossil beds and rock or san art, and the Joubert's Pass, with a gradient of 1:6, is the third highest pass in South Africa, treating travellers to an ever changing view of river gorges and majestic mountains, and a variety of birds, game, and alpine plants.

Lady Grey is classified as (Cfb) with a temperate oceanic climate without a dry season and warm summers, and is mostly clear year round. In December and January the temperature hovers around 26°C to 28°C and at night it cools down considerably to around 14°C. The winters are short, but cold with temperatures hovering around 14°C during the day, and 0˚C and 2°C at night, with occasional light snowfall of about 3mm, usually in June. The average annual temperature for Lady Grey is 22°C. Although it has no true dry season, there is a drying trend in the winter, and some sources say the annual precipitation is 287mm, while others say 608mm. The wettest month is December with an average of 43mm, and the driest month is August with only 7mm

Köppen Climate Classification: (Cfb & Cfa)

East London

East London is the gateway to the Wild Coast to the north, and sits at the northern end of a 300 kilometre stretch of coastline referred to as the "Sunshine Coast" which has St Francis Bay at the southern end. East London is another great example of climate types merging in the Eastern Cape, as it sits at a transition zone between a mild oceanic climate (Köppen climate classification: Cfb), bordering on a humid subtropical one (Köppen climate classification:  Cfa). However, some sources list East London only as Cfa?

The city lies between the Buffalo and the Nahoon Rivers, and is the only river port in South Africa. Although it has no true dry season, there is a drying trend in the winter, with the wettest times of year being spring and autumn. The temperature here averages 19.4 °C, and the annual rainfall is significant at 843mm. The all-time record low is 3°C, and although temperatures have never dropped below freezing since records began, East London has recorded snowfall in 1985 and 1989. An all-time record high of 44°C was recorded on the 13 March 2021, but generally the hottest temperatures are recorded in spring and autumn, rather than the summer months, due to berg winds which contribute to these high temperatures, as already warm air from the arid interior is further heated through compression as it drops over the escarpment to sea level.

Humid subtropical climate Köppen Climate Classification: (Cfa)

A humid subtropical climate is a zone of climate characterized by hot and humid summers, and cool to mild winters. These climates normally lie on the southeast side of all continents, generally between latitudes 25° and 40° and are located poleward from adjacent tropical climates, under the Köppen and Geiger climate classification.

Although many subtropical climates tend to be located at or near coastal locations, in some cases, they extend inland, where they exhibit more pronounced seasonal variations and sharper contrasts between summer and winter. As such, the climate can be said to exhibit somewhat different features depending on whether it is found inland, or in a maritime position.

Gqeberha (Port Elizabeth)

Gqeberha is classified as Cfa by Köppen and Geiger. It lies on Algoa Bay of the warm Indian Ocean, and the city climbs the foot of a 60 to 90m plateau, and occupies both banks of the small Baakens River. The residential area is on flat tableland, and the city's warm oceanic climate ranks it among the top cities in the world for pleasant year-round weather. The city represents a large percentage of South Africa's biological diversity and is a confluence point of five of the seven South African biomes, namely: Thicket, Grassland, Nama-Karoo, Fynbos and Forest Biomes.

The area lies between the Mediterranean type winter rainfall zones of the Western Cape and the hot and humid subtropical summer rainfall regions of eastern South Africa. It has a temperate oceanic climate with an annual rainfall around 526mm, and rainfall is well distributed throughout the year, except during severe droughts. August usually receives the most rainfall, and the least rainy months are at the height of summer from December to February.

In Port Elizabeth, the summers are short and warm, but considerably less humid and hot than more northerly parts. The warm season is from around November, December to March, with an average daily high temperature above 25°C. The hottest month of the year in Port Elizabeth is February, with an average high of around 27°C.The winters are long and cool, starting around April and May, through October with temperatures ranging from 7°C to 20°C.

Colchester & Cannonville

The tourist villages of Colchester and Cannonville are only 40km from Port Elizabeth, nestled on the banks of the beautiful Sundays River, only a few kilometres from the river mouth where it flows into the Indian Ocean through the majestic and world-renowned Coastal Dune Fields. The great sand dunes date back 100,000 years and are teeming with wildlife, and the Sunday’s river is a birders paradise.

These villages are classified as (Cfa) as the climate here is mild, and generally warm and temperate. The average annual temperature is 18.5°C, and the annual rainfall is about 511mm.

Boesmansriviermond

Boesmansriviermond is 25km from Port Alfred, on the west bank of the Bushman's River, just across the river from Kenton-on-Sea. It is type (Cfa) and the climate is warm and temperate with lots of rain even in the driest month. The average annual temperature is 18.7°C, and the rainfall is around 657mm per year.

Kenton-on-Sea

Kenton-on-Sea is type (Cfa), so the climate is mild and generally warm and temperate, with an average annual temperature of 18.7°C. It has a significant amount of rainfall during the year, even in the driest month, with an annual rainfall of 657mm.

Port Alfred

Port Alfred is situated at the mouth of the Kowie River, almost exactly halfway between the larger cities of Gqeberha and East London, and 30km west of Cannon Rocks. Its stretches of sandy beach extend for miles, and hiking trails navigate the river region, which is rich in indigenous vegetation, fauna and bird life.

It is classified as a (Cfa) type with a climate that is mild, and generally warm and temperate. There is a lot of rain even in the driest month, and about 596mm of precipitation falls annually. The average annual temperature is 18.9 °C.

Port St John’s

Port St John’s is situated on the Wild Coast alongside the massive Umzimvubu River, a river flowing through a gorge known as the "Gates of St John" into an estuary. The water has carved its way through the ancient rocks leaving two 300 meter ramparts towering on either side. Dense bush encroaches into the town and a short walk will take you into silent forests. The sea is always close, crashing onto the rocky shores which guard the secluded beaches.

It has a humid subtropical climate (Cfa) with rainfall occurring mainly in the summer months, with an average annual precipitation of about 1,089mm. The average annual temperature in Port St Johns is 19.7 ° and the temperature seldom drops below 14°C.  The highest average temperature in in Port Saint John’s is 26°C in January and the lowest is 19°C in June. The water temperature is between 23°C and 28°C.

Coffee Bay

Coffee Bay is a small community on the Wild Coast, known for its breath-taking views and beaches. It is classified as (Cfa) with an average annual temperature of 19.6 °C and an annual rainfall of 1,050mm.

Subtropical Highland Climate Köppen Climate Classification: Cwb

The subtropical highland variety of the oceanic climate exists in elevated portions of the world that are within either the tropics or subtropics. The subtropical highland climates tend to be essentially identical to an oceanic climate, with mild summers, but noticeably cooler winters.

Rhodes

Rhodes is also called the “tail of the dragon” as it's perched at the end of the mighty Drakensberg mountain range, and Drakensberg means 'dragon's mountain'.  This hamlet or small village lies alongside the wild trout rich Bell River, near Ben Macdhui in the north Eastern Cape, and was declared a conservation area in 1997 for its pristine surroundings. It sits virtually on the border with Lesotho, nestled at the foot of Naude’s Nek Pass, a long, slow, scenic drive on twisting gravel roads, either from Maclear or Mount Fletcher, over the Drakensberg to the village of Rhodes. With its summit at about 2,587m above sea level, the pass is the second highest dirt road in South Africa, and although it is usually travelled in a 4x4 vehicle, it still presents a challenge, particularly in winter when heavy snowfalls are common. In summer the days are hot and in winter there are usually deep snowfalls.

Rhodes is classified as a subtropical highland climate, (Cwb) with mild summers and chilly, dry winters, with occasional snowfalls. The average annual precipitation is 513 to 626mm, with the most rainfall occurring during the summer.

Hot and Cold Semi-arid Steppe Climates Köppen Climate Classification: (Types BSk and BSh)

Steppe climates like types: BSk (cold semi-arid steppe climate), and BSh (hot semi-arid steppe climate) are intermediates between desert climates and humid climates in ecological characteristics and agricultural potential. These semi-arid climates tend to support short or scrubby vegetation and are usually dominated by either grasses or shrubs

Hot semi-arid (BSh) climates are most commonly found in Africa, Australia and South Asia, and tend to be located in the 20° to 30° latitudes of the tropics and subtropics, typically in proximity to regions with a tropical savanna, or a humid subtropical climate. These climates tend to have hot, sometimes extremely hot, summers and warm to cool winters, with some to minimal precipitation.

Cold semi-arid climates (BSk) are most commonly found in Asia and North America. However, they can also be found in Northern Africa, South Africa, Europe, sections of South America and sections of the interior of southern Australia, and New Zealand.

Cold semi-arid climates tend to be located in elevated portions of temperate zones, typically bordering a humid continental climate or a Mediterranean climate. They are typically found in continental interiors some distance from large bodies of water. Cold semi-arid climates usually feature warm to hot and dry summers, though their summers are typically not quite as hot as those of hot semi-arid climates. Unlike hot semi-arid climates, areas with cold semi-arid climates tend to have cold winters, and these areas usually see some snowfall during the winter.

Because areas featuring cold semi-arid climates tend to have higher elevations than areas with hot semi-arid climates, they tend to feature major temperature swings between day and night, sometimes by as much as 20°C or more. These large diurnal temperature variations are seldom seen in hot semi-arid climates.

All the towns and cities I researched below were listed as (BSk) cold semi-arid climates types, but I believe some may be BSh.

Cold Semi-arid Steppe Climates Köppen Climate Classification: BSk

Addo

Addo is a town in Sarah Baartman District Municipality in the region east of the Sundays River, some 72km northeast of Port Elizabeth. In 1931 about 680 hectares were enclosed to form the Addo Elephant National Park. The climate here is classified as (BSk) local steppe climate, and there is little precipitation throughout the year, with an annual rainfall of 502mm, and an average annual temperature of 18.3°C.

Zuurberg Mountain Village

Zuurberg Mountain Village is situated high up on the Zuurberg in the Sarah Baartman District in Addo, set in 160 hectares of indigenous vegetation with breath-taking views of the famous Addo Elephant National Park, and a mere one hour’s drive from Port Elizabeth. It is classified as (BSk) with a local steppe climate, and little rainfall throughout the year. The average annual temperature is 17.1°C, and the yearly rainfall is 478mm.

Graaff-Reinet

Graaff-Reinet lies 750m above sea level and is built on the banks of the Sundays River, in the arid upland plateau area called the Great Karoo. Surrounded by the Camdeboo National Park, it is truly the heart of the Great Karoo, and this boundless and mysterious area is covered by broad plains which roll away to distant koppies and multilayered mountains. It is classified as a local steppe climate (BSk) and there is little rainfall throughout the year, with around 512mm annually, and the average annual temperature is 17.0 °C.

Nieu-Bethesda

Nieu-Bethesda is a village at the foot of the Sneeuberge, approximately 50 kilometres from Graaff Reinet. It is referred to as a (BSk) local steppe climate, where the average annual temperature is 14.7°C, and about 465mm of precipitation falls annually.

Middleberg

Middleberg lies in the upper Karoo, 1,279m above sea level, and is surrounded by beautiful mountains. The Sneeuberg Mountain range lies to the south, and during the winter months snow can be seen on the mountains, and the Lootsberg Pass becomes a spectacular winter landscape. It is known as a local steppe climate classification (BSk), and there is not much rainfall all year long, with only around 461mm annually, and the average annual temperature is 15.9°C.

Cradock

Cradock is a quaint town in the upper valley of the Great Fish River, 250km by road northeast of Port Elizabeth. The Swaershoek Pass is a major gravel pass located about 20km south-west of Cradock, and its approach roads offer some of the best Eastern Cape scenery imaginable. Although it has a very low rainfall, overall it has a pleasant climate, with hot and balmy summers and cold winters. The average temperature is around 16.0°C, and annual precipitation is 616mm. It is classified as (BSk), with a cold semi-arid (steppe) climate, but other sources list it as (Cfb) with an ocean or maritime mild winter climate which is confusing.

Valley of Desolation Graaff Reinet. Picture courtesy South Africa Tourism see their flickr pageValley of Desolation Graaff Reinet. Picture courtesy South Africa Tourism see their flickr pageBiomes & Biodiversity Hotspots in the Eastern Cape

The magnificent Eastern Cape forms a transition zone for a great complexity of flora and fauna types, due to its highly varied climate, topography, and geology. This has led to extremely high levels of endemism across its many different ecosystems, meaning that many of these South African species are found nowhere else on earth. It is the only province to contain all three of South Africa’s global biodiversity hotspots, namely: Cape Floristic Region, Succulent Karoo, and Maputoland-Pondoland-Albany.

Biodiversity hotspots are the world’s most biodiverse and threatened terrestrial regions, and for an area to qualify it needs to have a minimum of 1,500 species of endemic plants, and to have lost a minimum of 70% of its primary vegetation. These hotspots are heavily threatened by habitat loss and other human activities, and conservation of these species is vital.

Although grassland is by far the dominant biome in the Eastern Cape, it is the only Province with eight of nine South African Biomes, and includes twenty-eight named vegetation types. It incorporates five centres of endemism, the largest of which, the Albany Centre of Endemism, extends almost nine million hectares across the province.

Endemic species are those species that are found only in a limited, restricted, and defined area or habitat, with no traces of its populations in any other part of the world. Because endemic centres of fauna and flora are thought of as ‘islands’ their protection is a priority.

Click here to read more about South Africa’s biodiversity hotspots at the botanicalsociety.org.za

Nieu-Bethesda, Karoo, Eastern Cape. Picture courtesy South Africa Tourism see their flickr pageNieu-Bethesda, Karoo, Eastern Cape. Picture courtesy South Africa Tourism see their flickr pageGeology and Soils

For gardeners in the Eastern Cape it is just as vital to know your soil type, as it is to know the precipitation and climate of your region. Soil science is far too complex to address fully here, and I am no expert in this field, so I have included some links, should you wish to pursue this subject in more depth.

The flora of the various biomes grow on different soils, and studies done on the determinants of the boundaries of Forest, Fynbos, Grassland, Renosterveld and Thicket biomes in a 1,200 km² area of the Kouga region revealed that the most important variables in differentiating amongst biomes were, namely: rainfall, fire exposure, soil fertility, and soil drainage. The conclusions drawn from this study done in the Kouga region can be applied to similar biomes occurring in other regions of the Eastern Cape Province.

Soils of the majority of Fynbos and Grassland biomes are shallow, rocky and infertile. Grassland biomes are commonly found on seasonally waterlogged soils, while Renosterveld occurs on moderately drained soils of intermediate fertility.

Fynbos and Thicket biomes are found in areas prone to occasional wild fires, but the Fynbos is restricted to sandstone-derived soils, and the Thicket biome to shale-derived soils of deep to intermediate depth.

The soils of Forest and Thicket are free of rocks and deep and fertile, especially in terms of oxidizable carbon and total nitrogen. Forest biomes were restricted to sandstone-derived soils, and the relatively high fertility of both Forest and Thicket soils is largely attributed to canopy-induced enrichment in the form of fallen leaves and branches etc. which are able to decompose and enrich the soil in the prolonged absence of wild fires.

Click here to read the article in depth, from ScienceDirect.com

Boesmansriviermond. Picture courtesy Mike Smuts see his flickr pageBoesmansriviermond. Picture courtesy Mike Smuts see his flickr pageThese patterns can provide useful insights for gardeners to assess the determinants of the multiple boundaries in the biome-rich landscape of the Eastern Cape Floristic Region, and apply them to their own gardens and regions.

The geology of the Eastern Cape is characterised by sediments of the Cape Supergroup and the Karoo Supergroup, which were deposited above the Namqua-Natal Belt and the Pan African Belt about 60 million years ago.  The Cape Supergroup was deposited first and is characterised by the Witteberg group, Bokkeveld Group rocks and Table Mountain group rocks in the south, and Natal Group rocks in the east.

The Cape Supergroup is characterised by highly folded and contorted sandstones, quartizites and shales.

The Karoo Supergroup was deposited above the Cape Supergroup, and covers two-thirds of South Africa, and is made up of the Dwyka, Ecca and Beaufort Groups, over which the Stromsberg and Drakensberg Groups were deposited. This Karoo Supergroup contains glacial deposits (Tillite) of the Dwyka Group, fossiliferous shale of the Ecca Group and mudstone and sandstone beds of the Beaufort Group.

The Drakensberg and Stormsberg group were formed later by the outpouring of basaltic lavas resulting in the prominent outcrop in the northern portions of the province. Not all magma reached the surface, and some intruded into the older Karoo Supergroup rocks, resulting in the many dolerite intrusions found in the province.

Therefore, the geology of the Eastern Cape is dominated by younger sedimentary rocks, predominantly clay or sand based. This young, mainly sedimentary geology, combined with an unreliable rainfall, which for large parts is low, the soils of the Eastern Cape have a high percentage of mica, quartz and kaolinite, and are typically shallow, unstable and less developed, apart from those few areas that receive more reliable and efficient rainfall.

These less developed soils typically show low levels of nutrients, and especially so where they are farmed without suitable management, and because they are predominantly sandy and conditions are dry, soil erosion is a major problem in the Eastern Cape, especially when poor pasture management occurs. Only 18% of land is classed as arable, 63% is suitable for grazing, and 19% is only suitable for wildlife.

This article at researchgate.net on the mineralogy and fertility status of selected soils in the Eastern Cape may prove helpful for many gardeners and farmers alike.

Karoo Landscape Eastern Cape. Picture courtesy South Africa Tourism see their flickr pageKaroo Landscape Eastern Cape. Picture courtesy South Africa Tourism see their flickr pageThe evolution of the plants in the Cape has been governed by a couple of vital soil factors. Number one is whether the soil is calcareous or not, and whether it is calcareous as well as saline (salty). The second is how wet the soil becomes during the rainy months and how freely it drains. If you know what your soil type is, you will be able to determine, to a large extent, which plants it is likely to support.

Calcareous soils are those that have free calcium carbonate, a chemical compound with the formula CaCO₃. It is a common substance found in rocks as the minerals calcite and aragonite, and is the main component of eggshells, gastropod shells, shellfish skeletons and pearls. Calcareous soils are most often formed from limestone, or in dry environments where low rainfall prevents the soils from being leached of carbonates. These soils have pH values in the range of 7.0 which is neutral, to 8.3 which is alkaline. They are formed largely by the weathering of calcareous rocks and fossil shell beds like varieties of chalk, limestone, dolostone, or marl. Marl is an old term used to refer to an earthy mixture of fine-grained minerals. The term was applied to a great variety of sediments and rocks with a considerable range of composition. Calcareous marls grade into clays, by diminution in the amount of lime, and into clayey limestones.

Calcareous soils are common in arid and semi-arid regions of the world with little rainfall, and occur in various forms (powdery, nodules, crusts etc.) The high calcium saturation tends to keep calcareous soils in well aggregated form and good physical condition, and often calcareous soils can be very fertile, but they are generally thin and dry.

Although these soils frequently cause nutrient deficiencies for many plants, the potential productivity of calcareous soils is high where adequate water and nutrients can be supplied, and if they are managed properly, calcareous soils can be used to grow most crops and many garden plants, excluding those requiring acidic soils like blueberries, camellias and gardenias.

Whether you want to start a home garden, or farm on these soils, there are steps you can take to ensure success. Farmers should seek professional advice on soil analysis and fertiliser requirements for specific crops; and gardeners can apply some of the same principles for success. 

Because calcareous soils generally have low organic content gardeners can apply copious amounts of compost, or kraal manure to their garden beds; and if these are applied regularly they will slowly improve the texture and nutrition of the soil. Mulching is also most beneficial in these regions. Read more about mulching here.

The higher the calcium carbonate in these soils becomes, the more the pH increases, making the soil alkaline. This results in many nutrients being less available to plants, but especially Phosphorus. The effect of low P (phosphorus) solubility in calcareous soil is relatively poor fertiliser P efficiency. Phosphorus is involved in many plant processes, including: protein synthesis, energy transfer reactions, development of reproductive structures, crop maturity, and root growth. Unsuitable garden plants and crops for these conditions, and those incorrectly planted and fertilised will appear stunted, with shortened internodes and poor root systems, due to phosphorus deficiency.

In general, roots absorb phosphorus in the form of orthophosphate, but they can also absorb certain forms of organic phosphorus, and gardeners can apply suitable P fertilisers at regular intervals to keep their plants healthy. However, the addition of high cost P fertilisers to maintain sustainable agriculture is often not feasible for rural farmers.

Calcareous soils usually suffer from a lack of micronutrients, especially zinc and iron. Zinc deficiency is most pronounced in maize, especially under high yield intensive cultivation systems.  Zinc sulphate is an effective zinc source and is the most popular form in use for soil application, and a single application lasts for several years. Foliar applications of zinc are used on fruit trees, and heavy applications of animal manure are helpful in preventing deficiency of iron and zinc. For gardeners a product like Trelmix will supply all your plants macro and micro nutrient needs in one bottle.

Because calcareous soils generally have low organic matter content they also lack nitrogen. For edible crops the application of nitrogen through side-dressings to the growing crop is an efficient way of nitrogen application, but care should be exercised so as not to apply nitrogen too close to seeds as it may prevent germination. Ammoniac sources of nitrogen and urea should not be left on the surface of calcareous soils, since considerable loss of ammonia through volatilization may occur, and they should be incorporated in the soil instead. Volatilization is the conversion of a liquid chemical into a vapour, which escapes into the atmosphere.

Where calcareous soils contain an impermeable hard pan (petricalcic horizon) they should be deeply ploughed or dug over, in order to break the pan. Calcerous soils should also have an efficient drainage system, and furrow irrigation is better than basin irrigation on slaking calcareous soils, and on undulating lands, contour and sprinkler irrigations are better options than flood irrigation. Drip irrigation may also be practiced on these soils.

An easy scientific method which gardeners can use to determine if their soil is calcareous or not is to dilute one part battery acid with nine parts water and then add some soil. The acid reacts with the shell fragments to release the gas carbon dioxide, so if the water fizzes it is calcareous. White alcohol vinegar poured over a soil sample will also foam if the soil is calcareous.

Nahoon River East London. Picture courtesy South Africa Tourism see their flickr pageNahoon River East London. Picture courtesy South Africa Tourism see their flickr pageSelecting plants for your garden:

Once you have established your soil type and ascertained what the drainage is like, you will be well on your way to knowing which plants will thrive and which simply won’t. It is far easier to grow plants suitable to the soil in your region than to try to amend the soil. Once your garden is more established, you can always add a few potted plants or raised beds to grow some of your favourite exotic plants in.

The selection of plants available to grow on calcareous soils is far less than those adaptable to acidic soils, so when selecting the right plants for your Eastern Cape garden it is most important that you consult with your local garden centre. They know what does well in your area, so do not hesitate to ask them for advice.

If you are totally new to gardening in the region, friendly neighbours can give invaluable advice, or you many even decide to take a stroll through your suburb or local parks to take small cuttings of plants which appeal to you, which can be identified by your local horticulturalist. Even if you live on a small plot, planting a garden will help to stabilise soil, prevent dust and sand blowing into your house, create shade to cool the house, and provide a space for animals and plants to live – creating an ecosystem and supporting biodiversity.

Most importantly for gardeners to understand is that a number of floral habitats meet in the Eastern Cape, producing a range of different plants and environments. For this reason, gardeners are encouraged to plant mainly indigenous plants as they have evolved over eons to adapt to their local environment, and are the best choice for your main framework of trees and shrubs.

Indigenous plants have also developed a symbiotic relationship with many of the insects, birds and local animals over a long time, creating a complex system of life, and in order to sustain the huge variety of life forms in the eco-system, we must support, rather than disrupt it. In addition, local plants are adapted to the soil types and precipitation where they occur naturally and will require little supplementary watering – reducing the amount of water you need to keep your garden beautiful.

Remember, when planting indigenous plants it is most important that you chose plants that grow wild in your immediate vicinity, because plants from even a small distance away may cross-pollinate with other related wild species to form hybrids, and this may undermine conservation efforts. Be extremely careful not to plant any invasive alien species in your garden, as they are the greatest threat to biodiversity, and often also increase the risk of severe wild fires.

Because different localities present a variety of growing conditions, including rainfall, wind exposure and soil type, one plant list will not suit everyone. Compiling lists for each region separately is also most exhaustive, so for now, I have compiled general plant lists which will help you with your selection, but which will still require some homework on your part to hone your list down to only those plants which are perfect for your area.

I found this wonderful library of indigenous plants online, each plant has a beautiful photograph, and it covers all regions of South Africa, including the Eastern Cape, so be sure to visit The Plant Library for inspiration on what indigenous plants are available for your region. Click here to read more.

At a later date I will attempt to make plant lists specifically for the Eastern Cape, as this article is already far too long. Take a look at my articles and plant lists here: water-wise, subtropical regions, coastal gardens, and cold gardens.

I hope you found this article helpful and I also hope it inspires you to do more gardening in this magnificent region of our country.