Glenn Kinghorn was born January 5, 1894 in McCook, Nebraska. As a young boy, he moved with his family to Fort Collins, Colorado where he graduated from Fort Collins High School in 1912. He then attended the Agricultural College of Colorado (now Colorado State University) for three years until World War I interrupted his studies.
Following the war, he worked for the Great Western Sugar Co. before becoming farm editor of the Fort Collins Coloradoan newspaper in 1919. He later wrote a weekly column, "The Outdoor Gardener," for the Coloradoan in the mid-1960s.
In 1921, he became publications editor at the college. During those years, he also operated a local nursery with his father. He retired from the college in 1946, and worked a year as director of information for the U. S. Bureau of Reclamation in Washington, D.C.
In 1948, he returned to Fort Collins and worked in horticultural research for the Colorado Game, Fish and Parks Department before retiring a second time in 1963.
He died in Fort Collins, December 27, 1971, nine days short of his 77th birthday.