Although gardens frequently appear in historical accounts as important sites of scientific (or natural philosophical) research and practice through the 19th century, they are only rarely encountered in the literature on 20th century science. This is true even of botanical gardens, which once counted among the foremost sites of scientific exchange and knowledge production, let alone the more humble home or domestic garden, which was never accorded as significant a position to begin with. In this paper I return attention to the garden, and particularly the domestic garden, as a site of interest for historians of 20th century science and technology. I will present a study of the activities of amateur flower and vegetable breeders, a varied group of practitioners united in this study by their interest in applying genetics research to their efforts to develop new varieties of plants. In their attempts to adopt and adapt new tools and techniques drawn from genetic science – methods ranging from hybridization to the application of mutagenic agents – these amateurs turned their flower and vegetable gardens into experimental venues and undertook genetics experiments as leisure time activities.

As I argue in this paper, this study of experimental science and a domestic space encourages us to reconsider two common assumptions found within the literature of twentieth century science. The first is a narrative of twentieth century biology in which amateurs are assumed to have been excluded from experimental biology – as opposed to natural historical studies, where amateurs and professionals frequently interacted, sharing materials and methods. In the case of amateur plant breeding I describe, it becomes clear that experimental practices were not so exclusionary as has been assumed; some professionals encouraged amateur activities (one even going so far as to turn his amateur correspondents’ gardens into an extension of his laboratory) and others objected to them, but in either case they recognized a shared set of tools and practices. The second is the gendering of do-it-yourself science and technology as an activity undertaken primarily by men and boys, often with the intent of displaying or defending masculinity. Amateur plant breeding does not appear to have followed a similar trajectory as these other amateur traditions, with women participating much as men; this offers the possibility to reconsider the assumed role of gender in amateur science and technology.