This chapter connects the French introduction of fast-growing, exotic hard timber species in Vietnam to the intensive search for mine timber to support the coal mining industry. The filao tree known scientifically as Casuarina equisetifolia, and the eucalyptus were introduced in Vietnam by the French in 1896 for the dual purpose of harvesting their hard timber for mine props and using them to reforest the shifting sand dunes along the coast of Annam, a French protectorate in what is now central Vietnam. Through a long and complex process of growing and acclimating the trees to Annam’s coastal sand dunes, French foresters were able to successfully grow the filao in industrial-style plantations and nurseries. Their success helped establish the filao as a popular exotic hard timber species for the reforestation of coastal sand dunes, not just in Vietnam but also in other French colonies, such as Senegal and Madagascar. Overall, the stories of the filao shed light on transnational connections between coal mining and the environment during the age of the empire, when the mining-driven search for hard timber commodities transformed the landscapes of both Vietnam and Africa.