The theory of property developed by John Locke in the classical theory of property is still used in contemporary interpretations of property ownership, improvement, and development of land. But as his story is read in the context of current ecological disasters and in the context of sacred-forest traditions in Africa, its limits are made evident. This paper proposes that the labour theory of appropriation and the theory of improvement as propounded by Locke create a productivist quantification of the value of land that overlooks forests whose value lies more in the ecological, spiritual and social than in the agricultural or market value. This issue is brought to the fore in sacred forests in most African settings. They tend to be controlled by taboo, ritual, customary power and collective restraint, and they are not only biocultural landscapes but also biodiversity reservoirs, carbon storage and order in the community. Although Lockean natural-law system has some proto-sustainability provisions, particularly in the spoilage restriction and the enough-and-as-good clause, the emergence of money undermines these boundaries and assists in sanctioning enclosure, commodification and extraction. The paper also suggests that controversies of sacred forest borders shed light on a peace aspect that is usually ignored by the theory of property: forest controversies are not simply territorial controversies but controversies between incompatible legal and moral regimes of land management. In putting Locke into conversation with the sacred-forest traditions, the sustainability ethics, and environmental peacebuilding, the inadequacy of Lockean property theory is demonstrated in the article as well as the enduring impact that Locke continues to have.