In 1889, he was invited by José Manuel Balmaceda to Santiago, where he became a professor at the Instituto Pedagógico de Chile (together with the Germans Alfred Beutell, Friedrich Hanssen, Hans Steffen, Rudolf Lenz, Reinhold von Lilienthal, and Jürgen Heinrich Schneider). Here he remained for the next 36 years, retiring in 1925. Johow led a series of scientific journeys to the Juan Fernandez Archipelago, and in 1896 was author of a book on the flora of the islands titled Estudios sobre la flora de las Islas de Juan Fernández. He died on April 30, 1933, in Valparaíso.
Friedrich was the son of Carl Hermann Adalbert Johow and his wife Marie Luise, née Biehler. He had five siblings, his brother Georg Reinhold Franz Julius Johow (1862–1945) was Generalmajor of the German Army (German Empire) and Generalleutnant of the Wehrmacht (Tannenberg-General). Dr. phil. Johow was married to Magdalena, née Schäfer. They had three children: Margarita, Dolly, and Ernst Arnulf (1893–1965)