Walter H. Greenleaf was born in Germany, but received his education in the United States. He graduated with a B.S. from the University of California in 1936 and received his Ph.D. from the same university in 1940. He worked for the Georgia Agricultural Experiment Station from 1944 until 1947, when he left to join the Auburn University School of Agriculture and Agricultural Experiment Station staff. He served as a geneticist and professor of horticulture from 1947 until his retirement in 1982.

His accomplishments include the discovery of two tomato varieties, three pimento varieties and a Tabasco variety. He also served as the Alabama collaborator with the United States Vegetable Research Laboratory in Charleston, South Carolina. He was a representative to the National Tomato Breeders Roundtable and the National Pepper Conferance. His honors include membership in Sigma Xi and Gamma Sigma Delta, selection into American Men of Science, Who's Who in America, and he is a fellow of the American Association for the Advancement of Science.