C.H. Friedrich Hesse studied theology at the University of Göttingen from 1790 to 1792 and then became a teacher in Hannover. After passing the final theological examination with distinction in 1799 he was appointed to the Lutheran parish in Cape Town, arriving in September 1800. At first he preached in German, but gradually changed over to Dutch. He played an active role in public life in Cape Town, particularly in education. As representative of the Lutheran Church he served on the seven member "Council of Scholarchs", which controlled all education at the Cape under the guardianship of the Governor. Later he became the council's secretary for some years, for which he was paid a salary by the government. He was an intelligent man of irreproachable character and was well liked and held in high esteem by government officials, his parishioners and the general public. In Cape Town he married a Miss Bergh and they had seven children. When he left the Cape in 1817 he received a testimonial from the governor, Lord Charles Somerset, praising his work on behalf of the British and Foreign Bible Society and the education of colonial youth.
Hesse was keenly interested in natural history, particularly botany, and cultivated aloes and other succulents in his garden. His neighbour, the apothecary P.H. Polemann* encouraged him in his botanical researches. During his stay at the Cape he befriended several important scientific visitors, including Dr M.H.K. Lichtenstein* and Captain D. Carmichael*. In 1808 he sent a parcel containing 150 kinds of seeds, mostly from bulbous plants, to William J. Burchell*, then still on the island of St Helena. Burchell stayed with him upon his arrival at the Cape in November 1810. Early in 1816 the Dutch botanist C.G.C. Reinwardt* visited the Cape on his way to the East Indies; he tentatively identified 16 species of Aloe growing in Hesse's garden and asked him to collect succulents and other plants for Dr M. van Marum, a famous physicist at Haarlem. This Hesse did, sending van Marum a box with seeds or plants of various species of Aloe, Cotyledon, Crassula, Stapelia, and Euphorbia in 1817. Reverend C.I. Latrobe, who visited the Cape in 1815-1816, also described Hesse's garden as containing a great variety of plants, trees and shrubs. Carl H. Bergius*, who visited the Cape in 1816-1818, praised Hesse for his friendship and went botanising with him. Hesse is known to have sent ferns, grasses and sedges to Europe, as well as some lichens. The English botanist W. Herbert named the plant genus Hessea (Fam. Amaryllidaceae) after him. He was also commemorated in Erica hesseana, and in the name of one of the lichens he collected, Stictina hesseana.
Hesse sent a small collection of Cape insects to the mineralogist J.F.L. Hausmann* of Göttingen, who visited the Cape himself many years later. According to Reinwardt he also sent many important objects to the physiologist and anatomist Johann F. Blumenbach in Göttingen.
After his return to Germany Hesse became a minister at Nieuburg, then at Elbingrode (1822-1825), and finally at Hoya, but throughout remained in contact with the Lutherans at the Cape. He prepared both a German (1820) and a Dutch (1823) translation of Reverend C.I. Latrobe's Journal of a visit to South Africa, 1815-1816, adding some notes on the animals and plants mentioned. Both editions also contain three appendices compiled by Hesse. The first dealt with the cultivation of European and other exotic plants at the Cape; the second mainly with whaling at the Cape, while the third summarised some recent events and changes in Cape Town and the rest of the colony. Included in one of the appendices is a description of the slates and granites near Cape Town, while some other kinds of rocks and minerals found in the colony are briefly mentioned. A volume of his Cape sermons, in Dutch, was published post-humously in Hannover in 1833.