David Gehrig, landscape architect, died May 29 in his Wilmette home. He was 52. Mr. Gehrig operated A. Gehrig Landscaping in Wilmette, a family-owned business. Born in Lake Forest, Mr. Gehrig grew up in Evanston, attended Evanston Township High School, and served in the U.S. Marine Corps during the Korean War. He received his degree in landscape architecture from the University of Illinois. Mr. Gehrig is survived by his wife, Patricia; his parents, Alfred and Gertrude of Cortez, Florida, formerly of Evanston; three daughters, Carolyn Kocmond of Downers Grove and Elizabeth and Jennifer of Wilmette; a son, David of Wilmette; two grandchildren; and a brother, Alfred of Jan Juan Capistrano, California. The June 1 service took place at Wilmette Lutheran Church. Burial was in Memorial Park Cemetery.