He was the author, with Christian Friedrich Ecklon, of Enumeratio Plantarum Africae Australis (1835-7), a descriptive catalogue of South African plants.
Here he met Franz Sieber and was talked into a partnership with the aim of collecting and selling natural history specimens - a burgeoning industry in the 19th century.
In 1829 Ecklon returned to the Cape from Europe where he had sold his specimens through the Unio Itineraria run by Christian Ferdinand Friedrich Hochstetter (1787-1860) and Ernst Gottlieb von Steudel (1783-1856) at Esslingen.
Turning south again they crossed the Outeniqua Mountains, visiting George and Knysna, before following the Langkloof to Uitenhage and Algoa Bay, from where they shipped their collection back to Cape Town.
Zeyher then returned to Uitenhage where he found employment in the service of Joachim Brehm, an apothecary and collector who had created one of the finest gardens in the Eastern Cape.
[2] Apparently Ecklon's visit to Hamburg was cut short by a warehouse fire that destroyed the greater part of their collections.
Financially Ecklon was crippled and sold his personal set of specimens to Sonder before returning to the Cape in late 1837 or early 1838.
While in Uitenhage, Zeyher had put together an extensive collection of indigenous wood samples together with flowering and fruiting herbarium specimens.
Zeyher accompanied Joseph Burke in an organised expedition under the sponsorship of lord Derby and collected a substantial quantity of botanical specimens.