The Frederic H. Leubuscher Collection contains 106 duplicate 35mm slides documenting examples of Leubuscher's landscape architecture design work in New Jersey, New York, North Carolina, Rhode Island and other locations.

The Lois W. Poinier Collection documents the work of Lois W. Poinier, a self-taught garden designer who designed scores of gardens, most of them in New Jersey.

The Richard Marchand Historical Postcard Collection contains approximately 1,200 35mm slide reproductions of postcard images depicting early twentieth century architectural and garden views of over 600 private estates throughout the United States. The collection includes views of estates owned by popular movie stars of the 1920s and 1930s, including Charlie Chaplin, Mary Pickford, Douglas Fairbanks, Claudette Colbert and Buster Keaton.

The Corliss Knapp Engle slide collection contains 35mm slides of gardens, garden features, flower shows, and flora photographed by Corliss Engle, a self-taught photographer and horticulturalist. Much of the collection is comprised of photographic documentation of numerous private and public gardens that she visited throughout the United States. Of particular note are images of Engle's own garden in Brookline, Massachusetts, spanning three decades; they provide excellent insight into the development and evolution of a garden over time. Portions of the collection highlight Engle's involvement with the Garden Club of America and the GCA's Garden History and Design Committee. The collection also includes various notes, lecture scripts, brochures, programs and articles on garden and plant-related themes generated or compiled by Corliss Knapp Engle.

The Starr Ockenga Collection includes materials generated or compiled by Ockenga for the writing of her books, 'Earth on Her Hands: The American Woman in Her Garden' and 'Eden on Their Minds: American Gardeners with Bold Visions.' Both books feature several individual chapters, each describing a garden owner and their garden.

The Thomas Warren Sears Photograph Collection documents examples of the design work of Thomas Warren Sears (1880-1966), a landscape architect and amateur photographer from Brookline, Massachusetts. Sears, who was based for most of his career in Philadelphia, designed a variety of different types of landscapes ranging from private residences, schools, and playgrounds to parks, cemeteries, and urban housing developments located primarily in Pennsylvania, Maryland, and New York. In addition to some of Sears' design work, images in the collection document Sears' domestic and foreign travels, design inspirations, and family. The collection includes over 4,800 black and white negatives and glass lantern slides dated circa 1899 to 1930. While most images show private and public gardens, there are a significant number of unidentified views and views photographed in Europe during two trips he took there in 1906 and 1908. Few images are captioned or dated. In addition, there are over 50 plans and drawings, most notably for Balmuckety in Pikesville, Maryland and Reynolda in Winston-Salem, North Carolina, and 3 monographs by or about Sears.

The Ken Druse Garden Photography Collection contains approximately 45,000 film transparency and 35mm slide images, dating from 1978 to 2005, of gardens, garden features, and flora photographed by garden writer and photographer Ken Druse. The photographic images document numerous private and public gardens throughout the United States and a few in Canada. Many have appeared in Druse's own books and articles as well as those by other writers. Approximately half of the collection is arranged according to specific garden, the other half by garden feature. A small portion of the collection consists of slide lectures given by Druse. Some images are identified with general captions and dates. Images documenting specific gardens are sometimes accompanied by handwritten notes, garden descriptions, and articles. Annotations appearing on certain images indicate the publication in which they appeared. The collection includes 'outtakes' or bracketed images that give insight into Druse's photo shooting process.

The Eleanor Weller Collection dates from circa 1978-2006 and consists of documentation and research files relating to the Garden Club of America's Slide Library of Notable American Parks and Gardens (later donated to the Smithsonian Institution as the Garden Club of America Collection) and the book, The Golden Age of American Gardens: Proud Owners, Private Estates, 1890-1940, co-written by Weller, as well as thousands of photographic images of historic and contemporary gardens compiled or taken by Weller. Materials include correspondence, research notes, clippings, brochures, lecture scripts, photocopied images from archival repositories, and original and duplicate 35mm slides.

The Perry H. Wheeler Collection includes the design, client and business records of Perry H. Wheeler, a landscape architect best known for his work on numerous townhouse gardens in the Georgetown neighborhood of Washington, D.C., during the 1960s as well as the redesign of the White House Rose Garden in collaboration with Rachel Lambert ('Bunny') Mellon during the Kennedy administration.

This collection contains over 37,000 35mm slides, 3,000 glass lantern slides and garden files that may include descriptive information, photocopied articles (from journals, newspapers, or books), planting lists, correspondence, brochures, landscape plans and drawings. Garden files were compiled by Garden Club of America (GCA) members for most of the gardens included in the collection. Some gardens have been photographed over the course of several decades; others only have images from a single point in time. In addition to images of American gardens, there are glass lantern slides of the New York Flower Show (1941-1951) and trips that GCA members took to other countries, including Mexico (1937), Italy, Spain, Japan (1935), France (1936), England (1929), and Scotland. A number of the slides are copies of historic images from outside repositories including horticultural and historical societies or from horticultural books and publications. The GCA made a concerted effort in the mid-1980s to acquire these images in order to increase its documentation of American garden history. Because of copyright considerations, use of these particular images may be restricted.