This article argues that because of the perceived and real biological characteristics of the different species of the genus Eucalyptus, imperialists and settlers, and later governments and the elites of developing nations, planted eucalypts widely and created new socio-ecological systems that encouraged and reinforced divergent patterns of economic, social, and ecological development. Planting eucalypts changed local ecologies and encouraged a movement towards market-based capitalism that benefited settlers, large landowners, urban elites and middle classes, and capital-intensive industries at the expense of indigenous groups living in and near forests. This article analyses the globalization of eucalypts in four broad phases: first, an enthusiastic expansion and planting from 1850–1900; secondly, failure in the tropics from 1850–1960; thirdly, increased planting and success rates in the tropics from 1960–2000, and fourthly, a growing criticism of eucalypts that began in the late nineteenth century and blossomed in the 1980s during an intense period of planting in India and Thailand.