Free State National Botanical Garden
The Free State National Botanical Garden (FSNBG) is one of eight gardens managed by the National Botanical Institute (NBI, now SANBI) in South Africa, concentrating exclusively on cultivating and propagating South Africa’s indigenous flora. The Garden lies about 12 km north of the centre of Bloemfontein, the capital of the Free State Province. It is within a 130 km radius of Kimberley, the Free State Goldfields, and Maseru, Lesotho. The Bloemfontein City Council purchased the farm, Winters Valley, in 1965. It later transferred control to the Board of Trustees of the NBI, which officially opened the Garden on 22 February 1969. The 67 ha Garden straddles a valley between the Bloemfontein plateau to the south and a range of 200-m-high hills to the north. The most prominent of these, Monk’s Head, is at the western end of the range. It is linked to the Eastern Hill by a rocky ridge, known as the Central Hill. The Garden is divided into two main sections—the developed garden and the natural vegetation area.
Climate
At an altitude of 1,400 m and 420 km from the sea, the Garden has a continental
climate. Temperatures range from well below freezing in winter to over 38°C
in summer. Winter drought usually lasts six to seven months. It is followed
by summer rain that may be as little as 200 mm or as much as 1,200 mm per
annum. These variable conditions determine that the Garden must be used for
hardy plants suited to southern Africa’s central plateau.
Natural Vegetation Area
Ecologically this site is of great significance as it supports relics
of three vegetation types. The vegetation is broadly classified as Transitional
Cymbopogon–Themeda Grassveld, but it also includes woodland
on the southern slopes of hills, and an outlier community of karroid (semidesert)
plants on a spur of the Bloemfontein plateau.
On the wooded southern slopes of the hills, one finds species, such as Buddleja saligna (False Olive), Rhus lancea, R. ciliata, R. erosa, Olea africana (Wild Olive), Euclea crispa (Bush Guarri), Grewia occidentalis, Cussonia paniculata (Mountain Cabbage Tree), and Rhigozum obovatum (Yellow Pomegranate).
At ground level, tufts of Themeda triandra are interspersed with Aloe grandidentata, Senecio radicans, and Cheilanthes eckloniana (Resurrection Fern).
Valleys and kloofs have deeper, richer soils and support larger trees, including Acacia karroo (Sweet Thorn), Celtis africana (White Stinkwood), and Ziziphus mucronata (Buffalo Thorn).
Plants forming the undercover include Asparagus species, ferns, Stapelia flavirostris, and Pterodiscus speciosus.
The grassland area to the east of the hills is a relic of the vegetation that covered the area when a presumably cooler, wetter climate prevailed over the region in prehistoric times. Dominant species here are Themeda triandra and species of Eragrostis, reaching a Themeda–Cymbopogon climax. Bulbous plants that occur amongst tussocks are Boophane disticha, Brunsvigia radulosa, Nerine laticoma, Haemanthus humilis, Ammocharis coranica, Hypoxis hemerocallidea, and Albuca setosa.
It is believed that at a later stage, extremely warm, dry conditions prevailed and semikarroid vegetation covered the area. The Karoo hill in the northwestern corner of the Garden has gravelly dolerite soil, confined to small shallow depressions. Eberlanzia spinosa dominates with Euphorbia mauritanica. Colonies of small plants grow around them and amongst these are species of Euryops, Crassula, and Duvalia. Bare ground colonisers on the hill are Stomatium mustellinum, Anacampseros ustulata, and Ruschia griquansis.
The Developed Garden
The central portion of the garden has been laid out for the display and
cultivation of as many attractive and frosthardy species of the interesting
and varied flora of the Free State as possible. The developed garden includes
the following collections:
Bulb
collection
Medicinal
plants collection
Herbaceous
collection
Clivia
collection
Tree
and shrub collection
Bulb Collection
The bulb collection comprises approximately 25 species. Bulbous plants
from all parts of South Africa are cultivated, but most are summer-rainfall
and frost-hardy species, tolerant of the extremely low temperatures experienced
in winter. Part of the collection is housed under cover in the nursery, as
many of the species cannot withstand frost during winter in the garden. Only
the toughest bulbs, such as species of Hypoxis, Agapanthus,
Scilla, and Gladiolus can be grown with success in the open. The
main function of the collection is display.
Medicinal Plant Collection
The medicinal plant collection includes perennials, bulbs, trees, and
shrubs that are cultivated for their medicinal value. Two traditional buildings
form part of the landscape design, highlighting South Africa’s diverse cultures.
The main purposes of the collection are educational and display.
Herbaceous
Collection
The herbaceous collection includes plants such as Diascia, Plectranthus,
Leonotis, Nemesia, and a range of free flowering plants
that are used to great effect in the most visited parts of the garden. The
collection includes some of the most frost-hardy species. Though very much
restricted by climatic conditions, this relatively young collection is growing
rapidly. The function of the collection is display, with the main emphasis
on spring and summer when most of our 25,000–30,000 annual visitors come to
the garden.
Clivia Collection
The Clivia collection is currently being built up, but it is still
a relatively young collection. The objective is to accumulate as many forms
of Clivia as possible throughout their known distribution ranges, and
augment the material collected for display in the garden. Species represented
include C. miniata,
C. nobilis,
C. gardenii,
and C. caulescens.
Tree and Shrub Collection
This is a collection of trees and shrubs mainly from the central parts
of South Africa. The emphasis is on plants with horticultural potential and
those that are very hardy. It is represented throughout the garden with the
main Rhus collection—the largest and most complete collection in a
botanical garden in South Africa. It serves as material for display, research,
and education. Specimens from this collection are propagated for sale to the
public and distribution to other botanical gardens.
Maintenance of the Collections
Plant collections held in the Free State NBG are a valuable asset. A lot
of time and resources are dedicated to developing and researching them. Two
horticulturists are responsible for collections in the garden and at the nursery,
respectively. A maintenance plan is being established to ensure progress with
the documentation of the collections.
—Amadeus Mogale
SABONET News 7.3: 226
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