The paper considers the history of relationships between people and trees spanning the history of Ireland, focusing in particular on the heyday of the Celtic culture and the cult of sacred trees, the Celtic Revival which subjected nature to idealisation and aesthetisation, and the prosperity of the Celtic Tiger which became a symptom of the bankruptcy of ecological responsibility on the green island. The ecocritical perspective presented in the text helps consider, using ancient symbols (such as the Tree of Life) and poetry, the relationship of man with nature, which is a vital task in Ireland, painfully affected by the economic crisis and in the global scale during the anthropocene.