Born in North Manchester, IN, the youngest son of a Mennonite family, Garber would go on to become one of the most interesting and original of the late American impressionists.
As a youth, he studied with Frank Duveneck at the Art Academy of Cincinnati, and later at the Pennsylvania Academy with Thomas Anschutz and J. Alden Weir. In 1905 he received a fellowship to study abroad from the Pennsylvania Academy, and while in England he painted works that are the most strictly impressionist of his career.
On his return to America in 1907 he established a studio in Lumbersville in Bucks County, just north of New Hope, Pennsylvania, and in the ensuing years became a central figure in the New Hope art community.
During these years he developed two different modes of painting. His more conventionally impressionistic works were lightly painted with attention to the shape and detail of the subject matter. His other, more popular style was more decorative and poetic.
In 1919 he began teaching at the Pennsylvania Academy and at his retirement thirty years later was one of its most loved and respected instructors.