 Farmer's goalscoring prowess was also evident when representing South Australia in interstate matches, where he averaged five goals per game.Farmer's playing career ended during World War II when he went into the RAAF, where he served as a sergeant from April 1942 to July 1946.He took over the reins of coach for North Adelaide from Haydn Bunton for four seasons from 1949, winning the premiership in 1949 and 1952.