Recognizing a kindred spirit in Cézanne, Marchutz took an initial trip to the artist's native Aix-en-Provence, France in the summer of 1928 and emigrated there permanently in 1931. For the next three and a half decades, he worked and resided at the Chateau Noir, a Provençal farmhouse several kilometers east of town.
From 1934 to 1944, he earned his living as a poultry farmer, raising chickens in specially-constructed sheds on the grounds of Chateau Noir.
Because he was a German national living in France, Marchutz was placed in an internment camp in Les Milles in September 1939. Under an agreement to serve as a prestataire in the French army, he was released in February 1940 and called into service in May of the same year. Having been demobilized at the beginning of October, he moved back into the Chateau Noir, where he would spend the rest of the war in hiding. Due to the difficulties of enduring this period, he only produced small drawings on poor-quality paper. After the war, however, Marchutz reapplied himself to drawing and painting, in addition to developing a unique method of producing lithographs which he would refine for the rest of his life.
In 1954, the architect Fernand Pouillon became a patron, and in 1957, designed and dedicated a studio to the artist. Marchutz worked there continually for the rest of his life, and upon its completion in 1968, moved into the adjacent apartment.
The Institute for American Universities, an organization aimed at enabling American students to study abroad in France, hired him in 1959 to teach studio art classes. In 1972, he founded the Marchutz School of Painting and Drawing with former students William Weyman and Samuel Bjorklund. The school exists to this day.
Parallel to his own artistic endeavor, Marchutz became a specialist in the works of Cézanne and maintained close relationships with major art historians and scholars, including John Rewald, Lionello Venturi, Fritz Novotny, and Adrien Chappuis. Both Rewald and Chappuis consulted him in preparing their catalogues of Cézanne's oeuvre, and Marchutz co-authored and published several articles with Rewald, including a photographic study of Cézanne's motifs. Marchutz also played a central role in organizing the first major Cézanne exhibition in Aix, commemorating the fiftieth anniversary of the artist's death, as well as a second exhibition held in 1961.
Marchutz died on January 4, 1976 in Aix. His work can be found today in the collections of the Metropolitan Museum of Art in New York, the Louvre, the Musee Granet in Aix, and in numerous other museums and private collections around the world.