This dissertation investigates the influence of vitalist matter theories and the practical, operational techniques of alchemy on agricultural improvement projects in seventeenth-century England. It argues that the historical territory of alchemy is much broader than many historians of this subject have conceded over the past generation. In fact, among a subset of utopian social reformers in mid-seventeenth-century England, alchemy was both an expansive worldview that explained physical change in the cosmos as well as a set of practices that could be applied in multiple locations where generation, growth, and change were the ultimate goals. This included the question of botanical growth and, most imperatively, the necessity of improving agricultural production. This project engages with multiple, overlapping historiographical traditions, including not only the histories of chemistry, alchemy, and agriculture, but also environmental history, and particularly the unresolved tensions over whether early moderns envisioned nature as a practically infinite, exploitable resource under humanity’s dominion or as a fragile, finite territory in need of stewardship and conservancy. Many figures I examine were not only social utopians but also believed that human ingenuity—buttressed by empirical science and experimentalism, but constrained within prescribed divine parameters—could create agricultural and economic bounty irrespective of any natural limits. This cornucopian political economy and ecology emboldened mid-seventeenth-century agricultural reformers to devise alternative agricultural regimes that used alchemy as a tool in an attempt to improve crop yields, the potency of seeds, germination speeds, soil fertility, and artificial fertilizers. In terms of science, many of these figures sought an overarching theory of growth that could apply to everything from metals and minerals underground to plants and animals on earth to more abstract notions like the economy. This natural philosophy was often referred to as a “vegetable philosophy.” With the Hartlib Intelligencer Circle as its primary focus, this dissertation seeks to demonstrate how the post-Baconian scientific worldview of empirical, technocratic, and most importantly, manipulative applied sciences induced many to seek solutions to social ills through the application of the basic premises of alchemy to create economic and ecological conditions that would eradicate the need for war, the existence of hunger, the fear of crop failure, and presage a future era of abundance. The Hartlib Circle—named after the Prussian émigré to England and pan-continental intelligencer Samuel Hartlib—was a correspondence network of natural philosophers who shared the results of experiments and carried on theoretical discussions on themes ranging from alchemy, mineralogy, and mathematics to pansophism, educational reform, and the English settlement of Ireland. This loose intellectual community was highly influenced by Paracelsian matter theory and the sal nitrum school of alchemy, which viewed salts as the key to unraveling the nature of matter and salts as the starting point for manipulating nature. For the Harltib Circle’s Paracelsians and sal nitrum theorists, alchemy was not simply transmuting lead into gold but rather transforming any natural substance such as plant matter, soil, water, animal manures, salts, and ash to solve a number of practical problems related to husbandry. These included, among other things, the manufacturing of saltpeter for use as a field fertilizer, the creation of seed steeps and “fructifying waters” to confer fertility on seeds using alchemical recipes, the application of alchemical theories of growth to understand soil fertility, and using alchemical techniques like calcination, fermentation, distillation, and putrefaction to uncover the underlying nature of plant life. The Hartlib Circle—and especially members interested in matter theory, such as Frederick Clodius, Gabriel Plattes, Benjamin Worsley, Johan Moriaen, and John Beale—sought to apply vitalistic theory and its alchemical outcomes with a keen interest in participating in the “improvement” of the natural world for human benefit. This project adds another dimension of this history that views vitalistic alchemy as a study of the intersection of inert and living matter, the practice of which was often done by “amateurs” in the field—on English farms, gardens, orchards, kitchens, and other everyday spaces—as opposed to just in the laboratory.