In 1856 Sachs graduated as doctor of philosophy, and then adopted a botanical career, establishing himself as "Privatdozent" for plant physiology. In 1859 he was appointed physiological assistant to the Agricultural Academy of Tharandt (now part of the Technical University of Dresden) at Julius Adolph Stöckhardt; and in 1862 he was called to be director of the Polytechnic at Chemnitz, but was almost immediately transferred to the Agricultural Academy at Poppelsdorf (now part of the University of Bonn), where he remained until 1867, when he was nominated professor of botany in the University of Freiburg.