In an effort to cope with the increasing demand for trees, the emergent economic elite of Bogotá imported and actively planted eucalyptus throughout the hitherto grim and treeless city. This article explores the socioecological context and mechanisms that led to the adoption of the blue gum (Eucalyptus globulus) in Bogotá during the late nineteenth century and the unforeseen consequences of its generalized use. Despite the city’s location in one of the world’s most biodiverse regions, the late nineteenth-century modernization of Bogotá relied primarily on this introduced fast-growing and highly adaptable tree. The biological properties of eucalyptus made it an inexpensive and fast-working solution to meet the increasing demand for raw material and ornamental trees. Following a period of enthusiasm for eucalyptus in the late nineteenth century, the tree’s large size, poor wood quality, and enormous water demands proved detrimental, and its use declined. By the 1920s, the use of eucalyptus in urban forestry was discontinued, and a more nuanced understanding of the role of urban trees took hold. Now naturalized, this hard-working tree continues to play an important role at the margins of the city as a medicinal plant and as a source of fuel wood in periurban areas.