Witwatersrand National Botanical Garden
The Witwatersrand National Botanical Garden (WNBG) was proclaimed in 1982 with the collaboration of the Roodepoort City Council (now the Greater Johannesburg Metro Council-Western MSS) and the National Botanical Gardens (now the National Botanical Institute). The valley with the 70-m-high Witpoortjie Waterfall, striking cliff faces, and resident breeding black eagles was the ideal backdrop against which to set a National Botanical Garden in one of the greater urban areas of the country.
Contributions of land from various organisations (in particular the Krugersdorp City Council) over the years have resulted in an estate of 300 ha today. Initially, the site had four small houses and one larger house. The original farmhouse was adapted to the garden office complex and also served as the curator’s house for a number of years. Most of the other houses and sheds were demolished, with the exception of one small house in the centre of the garden, which was altered to serve as a tea garden and restaurant.
During
the early development of the garden, all alien vegetation was removed and
today the garden specialises exclusively in the indigenous flora of southern
Africa, with a strong emphasis on plants of the Highveld region in which
the garden is situated.
All evidence of the original farm has now been skilfully transformed and landscaped into popular gardens for all to enjoy. The garden has a unique naturalistic landscaping style that combines both natural and wild areas with great success. Over the years, visitor numbers have increased to more than 130,000 per year.
Natural
Areas
The natural areas of the WNBG form over 300
ha of nature reserve in the heart of a developing urban sprawl. An absolute
asset to the city and its community, the garden also acts as an in
situ collection of over 600 plant species. The reserve is also
home to a very popular pair of breeding black eagles that are monitored
on the Internet by enthusiastic nature lovers every year during the breeding
season.
Collections
One of the main objectives of the WNBG is to
establish and curate collections of southern African plants according to
horticultural, scientific, conservation, and educational considerations.
The core collecting area for the garden has been defined as the summer rainfall
area of the southern African sub-region, south of the Zambezi River, concentrating
on the grassland biome and including the high altitude vegetation types
of the savannah biome. Species worthy of conservation are also cultivated
and maintained as genetic resources.
During the early years of the garden’s existence, much time was spent removing old farm developments and implementing new plans from scratch. As a result, living collections only became a priority to the garden during the latter years, once suitable structures and facilities had been built.
Collections are housed in the nursery, in the garden itself with a greenhouse and a shade house for Clivia, and a succulent growing facility for the succulent garden. A suitable potting shed and seedling nursing facility are being planned.
Grassland
As the garden is situated within the grassland
biome of South Africa, the WNBG grows many grassland species and spends
much time interpreting grasslands to the public. Included in this aspect
of the garden is a collection of grass Aloe, which is almost complete,
as well as a small collection of grassland cycads. Most of the focus is
on grasslands as a threatened habitat type; there are also various collaborative
projects with provincial nature conservation bodies cultivating threatened
grassland species.
The grassland element has successfully been incorporated into the naturalistic style of the landscaped garden by setting aside certain areas as grassland flower beds that are cultivated to look like grasslands, but contain many non-grass species, such as bulbs, cycads, and aloes that are typical of the grassland habitats.
A large area has been dedicated to the display of local wild flowers in a natural grassland setting. Grassland species from development sites in the area around the garden are rescued and transplanted into this area with the aim of displaying the diversity of our local flora to visitors.
Theme
Gardens
Cycads
As a flagship species of South Africa’s
flora, cycads form an integral part of the overall landscaping of the garden;
there is a central cycad garden where most of the specimens are held. Many
of the South African species of Encephalartos, as
well as Stangeria are on display
in the garden. The majority of plants have been donated either by Nature
Conservation or by private owners. A cycad propagation programme has been
established; cones are hand-pollinated and young plants are made available
for sale.
Succulents
As South Africa is home to such a wealth
of the world’s succulent flora, it is important for an indigenous garden
to have them represented if the climate allows. In the WNBG, the succulent
garden is under intensive redevelopment and will ultimately be an attractively
landscaped route through a rockery with both succulent and non-succulent
plants cascading over the rocks and cobbled pathways. Because of frost,
summer rainfall, and clay soils, the cultivation of succulents can prove
challenging. The WNBG focuses mainly on summer rainfall succulents (including
species of Aloe, Euphorbia, Stapelia, Crassula, and
many others), which can tolerate a moderate degree of frost.
Waterwise
Display Garden
In the Waterwise garden, made possible by
generous sponsorship, various aspects of water conservation through responsible
gardening techniques and the planting of indigenous plants are demonstrated.
Locally indigenous plants are widely utilised and practices, such as mulching,
composting, and effective garden planning are explained to garden visitors.
Arboretum
Consisting mainly of naturally occurring
species, the arboretum will need many years to mature, as many other young
trees have been planted between the larger ones. Ultimately, the entire
area will consist of rolling lawns and an interesting collection of South
African trees.
Water
Garden
The narrow stream that cascades past the
restaurant contains a wealth of aquatic and marginal plants. This is
a colourful portion of the garden with species, such as Hesperantha
coccinea, various Kniphofia species,
and many other flowering marginals. This garden feature is enjoyed by many
visitors to the garden and is especially popular with the children who look
for fish and tadpoles in the ponds.
Forest
Walk
The quiet Forest Walk has been skilfully
carved through riverine forest. Under the canopy of large Combretum
erythrophyllum, Kiggelaria africana, and Celtis
africana, many species from the forests of South Africa have
recently been planted. Most of these species will not grow in the open areas
of the garden, but are thriving in the shady, protected areas in this section.
This area is also well known by birders as the place to see shy cuckoo species
during the summer months.
Fern
Trail
Although not only ferns are grown here,
fern species form the overall theme of the Fern Trail. Many interesting
forest species, such as Streptocarpus and
Clivia, as well as Begonia and
forest understorey shrubs like Plectranthus spp.,
Tinnea barbata, and Mackaya
bella, complement the natural planting style. Clivia makes
an outstanding show in spring each year when they bear their large orange
flowers.
Bushveld
Meander
Originally a stretch of grassland, the Bushveld
Meander area has been transformed into a bushveld theme by increasing the
number of tree clumps and planting species of bushveld tree, shrub, and
aloe. The specific aim of this section and the adjacent grassland section
is to interpret the two main vegetation types, which constitute much of
the northern provinces of the country, and to show how they differ. Acacia,
Combretum,
and other typical bushveld species have been
planted in this area. As it is essentially an extension of the Arboretum,
it will also need many years to come to full maturity.
Grassland
Wild Flower Walk
The Wild Flower Walk is made up of mostly
open, but also sparsely wooded, grassland. The area serves as an educational
display of a natural grassland system within the bounds of a botanical garden.
It is an asset, not only to the learners and visitors to the garden, but
especially to all the permanent residents—birds, small mammals, and reptiles—which
make extensive use of the area.
Sasol
Dam and Bird Hide
The Sasol Dam is a large, artificial pond
with an adjoining bird hide surrounded by natural vegetation. It is a quiet
retreat and a favourite spot for both visitors and birds.
Sasol
Wetland Walk
Bordering the Sasol Dam, the Wetland Walk
consists of 100 m of planked boardwalk. It gives visitors the opportunity
to walk into a normally wet area that is also notoriously rich in bird life.
The altered habitat allows for the display of many typical wetland plants.
Crinum bulbispermum, Zantedeschia aethiopica,
and other marsh-loving plants flower in profusion.
Special
Collections
Clivia
The nursery in the garden holds a collection
of special clivias for use in the annual Clivia display, held at
the restaurant between September and October each year. The collection includes
beautiful selections and hybrids of various colours and shades from some
of the best breeding stock in the world.
Plectranthus
Despite frost during the winter months,
the garden also has an almost-complete collection of South African Plectranthus species. The collection includes
various hybrids and selections, with a very colourful result in the autumn
months.
Ledebouria
and Drimiopsis
Over the past few years, the garden has
put together a complete collection of all the South African Ledebouria and
Drimiopsis species.
The
Future
Although already a very popular and attractive
garden, the WNBG is still in the early stages of development. Less than
20 years old, most of the living collections are yet to be fully developed
and in many cases, the specimens (especially the trees) still have a lot
of growing to do. With its tremendous support base in the local communities
as well as corporate sponsorship, the WNBG has considerable potential to
grow beyond anyone’s expectations.
—by Andrew Hankey & Sharon Turner
SABONET
News 6.2:104
