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 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 Maida Babson Adams American Garden Collection documents the work of Molly Adams, a free-lance garden photographer who photographed hundreds of private and public gardens, many of them in the mid-Atlantic region, from the late 1950s through the mid-1990s. It includes slides, photographic prints, negatives and transparencies. A significant number of images document the work of landscape designers Nelva M. Weber, Alice Recknagel Ireys, and Friede Stege. Roughly 50 gardens do not have an identified location. Some images have captions and other information written on them.

The Roche Collection documents some of the work of John and Mary Alice Roche, garden photographers who photographed numerous gardens throughout the United States. Several of the Roches' images appeared in popular gardening magazines and books on flower arranging from the 1950s and 1960s.

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 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 Bedman Brothers Company Records collection focuses primarily on the business and financial transactions of Bedman Brothers seed company of Rahway, New Jersey, and includes accounting ledgers, purchase orders, price lists, miscellaneous business and family correspondence, and various brochures, pamphlets and leaflets related to horticultural topics. Other holdings in the collection include World War II ration stamps and two scrapbooks, one of which contains many late nineteenth and early twentieth century chromo-lithographed trade cards (primarily from the sewing, clothing, and floral industries). The other scrapbook holds news clippings from the Civil War period. Seperated materials include seed gathering equipment used by field workers.

The American-Moninger Greenhouse Manufacturing Corporation Collection includes 306 architectural plans and drawings of greenhouses, solariums, conservatories, garages, and other structures designed by American-Moninger for clients throughout the United States dating from 1923 to 1964.

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.