C.F.H. Ludwig (later von Ludwig) served an apprenticeship in a pharmacy in Kirchheim, near Stuttgart, and in about 1804 obtained a position in Amsterdam, first with an apothecary and then at a chemical laboratory. Learning that Dr F.L. Liesching* required an assistant in his pharmacy in Cape Town, he successfully applied for the post and left for the Cape in October 1805. He arrived during the period of uncertainty at the time of the second and final annexation of the Cape by the British. The Supreme Medical Committee appointed by the new administration approved his pharmaceutical qualifications in August 1807, listing him as one of nine apothecaries, chemists and druggists that were allowed to practice in Cape Town. In January 1816 he married Alida M. van de Kaap, widow of C.F.H. Altenstaedt, through which he acquired a tobacco business and a large property in Longmarket Street where they resided. They eventually had three sons and two daughters. Ludwig was a successful businessman and became affluent.
His scientific interests and talents led him to become a collector of natural history specimens, probably from about 1815. One of his fellow collectors was Ludwig Beil* with whom he collected plants near Swellendam in October 1826 and in the Caledon and Swellendam districts in January 1839. During 1826 Ludwig sent collections of plants, insects, shells, and more than a thousand birds to the Koenigliche Naturalienkabinet (Royal Natural History Museum) in Stuttgart. As a result the King of Wuerttemberg made him a Knight of the Kronenorden (Order of the Crown) of Wuerttemberg, which enabled him to assume the title Baron, and to be addressed as Freiherr von Ludwig. During a visit to Wuerttemberg in 1828 he presented a further collection of mammals, birds, reptiles, and Indian and American implements to various institutions, and the University of Tuebingen awarded him the honorary degree Doctor of Philosophy (Phil Dr). He arrived back at the Cape in April 1829. Further collections of birds were sent to Stuttgart and Frankfurt in 1832 and 1833. The specimens were mostly not collected by himself, as he did not travel extensively. Among others he acquired collections of insects from C.L.P. Zeyher* and birds from Dr Andrew Smith*.
At the close of 1829 Ludwig bought about one hectare of undeveloped land in Kloof Street, Cape Town, and began establishing a botanic garden to which visitors were later admitted by ticket. F.E. Leibold* was superintendent of the garden from 1834 to about 1837, when he was succeeded by James Bowie* who remained to about 1842. The gardener Thomas Draper* then took over until Ludwig's death. This beautiful and delightful garden became famous in the colony and was generally known as Ludwig's-burg. He cultivated a wide variety of plants, shrubs and trees, including fruit trees, vegetables and crop plants. As a corresponding member of the horticultural societies of London, Calcutta and Massachusetts he exchanged information and specimens with a variety of persons overseas. Thus many ornamental trees, shrubs, bulbs and other plants were obtained from all over the world, while many local plants were acquired from collectors such as J.F. Drege*, C.F. Ecklon* and Zeyher. Altogether he imported over 1600 species and varieties, including the jacaranda tree, and acclimatised them to Africa. As is to be expected some of them turned out to be unwelcome additions to the local flora. His botanical efforts were recognised both locally and overseas: The South African Institution praised him for his attempts to naturalise exotic trees in its annual report for 1830/1831; a volume of Curtis's Botanical Magazine (1835) was dedicated to him by W.J. Hooker, whose son, J.D. Hooker*, visited the garden in April 1843; and W.H. Harvey* dedicated his Genera of South African plants to him in 1838, having named the bulb Tulbaghia ludwigiana after him the previous year. Other plant species named in his honour were Restio ludwigii, Hibiscus ludwigii, and Hypoxis ludwigii. His herbarium specimens went to Berlin, Oxford, and Kew Gardens.
Ludwig was involved in many business ventures and participated actively in public life at the Cape. Among his friends were Harvey, the visiting astronomer J.F.W. Herschel*, botanist Dr C.W.L. Pappe*, and Dr N. Wallich* of the Calcutta Botanic Garden. As a leading figure in the cultural life of Cape Town he participated in the work of several scientific and other societies. In 1824 he was a member of the group of prominent citizens who attempted to establish the South African Literary Society in Cape Town, but permission to do so was refused by Governor Charles Somerset. After the society was finally established (in 1829) Ludwig served on its committee from June 1831. He served also on the council of the South African Institution (a purely scientific society) from its foundation in 1829 until it merged with the South African Literary Society in 1832 to form the South African Literary and Scientific Institution. Thereafter he served on the council of the latter body (as joint vice-president for several years) to about 1838. In 1830 he lent his collection of birds to the museum of the South African Institution (a forerunner of the South African Museum), and in 1833 contributed further material, including a collection of minerals from Wuerttemberg, and insects from China and Germany. Another movement in which he played a leading role was the Cape of Good Hope Association for Exploring Central Africa, which sent Dr Andrew Smith* on an expedition into the interior. It was founded in 1833 as an offshoot of the South African Literary and Scientific Institution. Ludwig, as one of its shareholders, was elected a member of its management committee from its inception to his death. He participated in drawing up instructions for the expedition, and received the thanks of the committee for offering to lend the expedition some scientific instruments. He served also on the committees of the Cape of Good Hope Agricultural Society (1836-1847) and the South African Public Library (1843-1847). He was a council member of the South African College from 1839 to 1842, and again for some time from July 1844.
In 1837 he again visited Wuerttemberg and presented valuable collections of birds, shells, insects and mammals to the Koenigliche Naturalienkabinet in Stuttgart; seeds to the city's Botanical Garden; mammals and birds to institutions in Darmstadt and Frankfurt; and 500 zoological specimens, seeds and a herbarium to the University of Tuebingen. The latter awarded him an honorary Doctor of Medicine (MD) degree in May 1837. He also received the freedom of the city of Stuttgart, and was again honoured by the King of Wuerttemberg. During this visit he met C.F.F. Krauss*, who assisted him in classifying his collections, became a friend, and accepted his invitation to undertake a state subsidised collecting expedition to the Cape. Krauss later described his shells and named some species after him. Two South African bird species were also named in his honour: Neotis ludwigii (Ludwig's bustard) and Dicrurus ludwigii (Square-tailed Drongo).
From about 1839 Ludwig experienced problems with his health and periods of depression. In addition his wife died in April 1840. None the less he was instrumental in founding the Cape of Good Hope Gas Light company in July 1844, and served as its first chairman to the time of his death. In March 1846 he became the first chairman also of the South African Mining Company. His interest in mineralogy was of long standing and he posessed a superb collection rocks and minerals. In June 1847 he was married for the second time, to the widow Eliza Bridekirk, but died a few months later. He was a highly respected citizen of Cape Town, a generous person, affectionate by nature, always ready to assist his friends, and a public-spirited businessman. With his children he was over-indulgent and later had serious difficulties with them. Ludwig's-burg was sold by auction in June 1848 and three months later the new owner offered its plants for sale. A number of them were planted in the revitalised Government Botanic Garden in Cape Town.