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 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.

Collection consists of 183 35mm photographic slides that Dr. John M. Fogg took of a variety of arboreta, botanic gardens, plant nurseries, and other assorted gardens throughout the United States and Canada between 1955 and 1967.

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.

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.

The Historic Gardens Postcard Collection includes 200 postcards of historic views of various public gardens, parks, monuments, and buildings throughout the United States and some foreign countries, including Canada, France and Cuba. Some private gardens and estates and many Washington, D.C. attractions are also represented. Roughly half of the postcards were mailed; the remaining postcards were not written on or posted. Areas represented include Arizona, California, Colorado, Delaware, Florida, Illinois, Indiana, Maine, Maryland, Massachusetts, Michigan, Minnesota, Nebraska, New Jersey, New York, Ohio, Oregon, Pennsylvania, Texas and Virginia. Foreign views show gardens in Havana, Paris, and Canada. About a dozen cards feature various views of Smithsonian Institution museums along the National Mall in Washington, D.C.

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 J. Horace McFarland Collection includes over 3,100 photographic images of private and public gardens throughout the United States, as well as some from foreign countries, dating from 1899 to 1963. Many of these images, generated for Mount Pleasant Press (later the J. Horace McFarland Company), were used to illustrate trade catalogs published by the firm as well as journal and newspaper articles. The collection also contains color records that were used as reference aids during the printing process, plant patents, and various publications of the McFarland Company.

The Mildred N. Beauregard Slide Collection contains 1,249 35mm slides, dated circa 1947-1971, of gardens and castles in England, Scotland, France, Holland, Switzerland, Sweden, Norway, and Denmark, as well as American gardens, photographed by Mildred Napier Beauregard. Some slides show tourist sites and scenes including skylines, rock features, waterways, boats and ships, and unidentified individuals. The collection also includes two slide viewers.