James Gamble Rogers' firm designed the layout and pathways of the West Garden. Between 1918 and 1929, acclaimed landscape architect, Beatrix Farrand, designed and installed the East Garden, created a new planting plan for the West Garden, and constructed the Boxwood and Alpine Gardens. She also designed the ironwork and benches. The garden design combines Mrs. Farrand's innovative use of plant materials and textures with Mrs. Harkness' color preferences and extensive collection of oriental garden statuary.
Beatrix Farrand, niece of Pulitzer Prize winning novelist Edith Wharton, was one of the original founders of the American Society of Landscape Architects. Only three other major examples of Beatrix Farrand's work remain, the most notable being Dumbarton Oaks in the Georgetown section of Washington D.C.
Upon Farrand's retirement from practice, Mrs.Harkness, shortly before her death, engaged another prominent female landscape architecture pioneer, Marian Coffin, to create a new planting plan in 1949 for the East Garden. Marian Coffin worked extensively for the DuPont family.