His father, Daniel Weitsche, was a bricklayer. For a short time, he attended the Latin School in Osterwieck, then worked as a clerk in Wolfenbüttel. In 1744, after three years in the service of a Captain named Von Blum, in Braunschweig, he became a soldier.
During his military service, he taught himself how to paint by copying works, possibly at the behest of a commanding officer who learned of his early interest in art. By 1756, he had become skillful enough to obtain a position as a porcelain painter at the Fürstenberg China Factory. In the 1760s, he began to create oil paintings; primarily local landscapes and scenes from the Harz region. In 1780, he and Johann Heinrich Ramberg made a trip through the Harz Mountains, and published an album with 12 views that served to establish his reputation.[3]
He also occasionally worked as an art dealer and, for several decades, was employed by the lacquerware manufacturer, Stobwasser [de], as a painter and trainer. In 1784, he was named a member of the Kunstakademie Düsseldorf. Five years later, he was appointed "Inspector" (a type of Curator) for the art gallery at Salzdahlum Castle. He became a member of the Prussian Academy of Arts in 1795.
In 1748, he married Anna Stoppen. Their sons, Friedrich Georg Weitsch and Johann Anton August Weitsch [de], both became painters. Anna died in 1783 and he remarried; to Sophie Helmkampf. In 1803, Johann succeeded his father as Inspector at Salzdahlum Castle.
