I am a historian, specializing in the environmental history of tropical crops, especially coffee. I teach in the history department at the University of Guelph, a vibrant comprehensive university located in the lovely city of Guelph, short drive west of Toronto, Canada. My first book, States of Nature: Science, Agriculture, and Environment, 1760-1940, focused on the expansion of the plant sciences in the Spanish-speaking Caribbean. Since then, I have done research on the environmental history of cacao cultivation, and most recently on the environmental history of coffee cultivation. I have been particularly interested in the origins and impact of plant pathogens on these tropical commodities. My latest book is Coffee is Not Forever: A Global History of the Coffee Leaf Rust, published by Ohio University Press in 2019. Many of my publications are available for free download at my academia.edu website and on my ResearchGate site. I post historical and other images of coffee on my Instagram feed.