In 1913 Steele embarked on a four-month tour of Europe to study European designs. Upon his return to America, he opened his own practice. His early garden plans are generally in the English Arts and crafts style of Gertrude Jekyll, Reginald Blomfield, and T. H. Mawson, but ornamented with Italianate detailing such as balustrades, hedges, urns, statuary, stone pineapples, and flights of water steps. During World War I, Steele served in the American Red Cross in Europe. After war's end he regularly returned in summers. His conversion to an Art Deco style began in 1925 when he visited the Exposition Internationale des Arts Décoratifs et Industriels Modernes and saw its examples of cubist gardens with mirrors, concrete and coloured gravel. By 1930 Steele was writing with enthusiasm of André Vera, Tony Garnier, and Gabriel Guevrekian. Steele's designs and writings of this period were influential during the stylistic transition from Art Deco to Modernism. He helped shape Modernism through younger design students at Harvard, notably Dan Kiley, Garrett Eckbo, and James C. Rose, to who Steele showed the possibilities of modern art and the creativity inherent within the design process. Kiley later wrote that "Steele was the only good designer working during the twenties and thirties, also the only one who was really interested in new things." Eckbo noted that "Fletcher Steele was the transitional figure between the old guard and the moderns. He interests me because he was an experimenter." Steele's own designs, however, were sufficiently removed from the Modern style so that his works were generally out of fashion until the modern era had passed. Steele is interred in the Mount Hope Cemetery in Rochester, New York. His papers are archived in the Library of Congress, the and in the , State University of New York College of Environmental Science and Forestry, Syracuse, New York.Images from the Steele manuscript collection can be found in the .
The House beautiful gardening manual; a comprehensive guide, æsthetic and practical, for all garden lovers, both those who are still planning their gardens on paper and those who have had gardening experience, including plant lists compiled with the help of horticulturalists in all sections of the country, and an introductory chapter on garden design by Fletcher Steele, Boston, The Atlantic monthly press, 1926.
Gardens and people, Boston, Houghton Mifflin, 1964.
