This dissertation shows how trees, and practices performed upon them, helped Christians and others in late antiquity understand both themselves and the arboreal world. A tactile relationship with trees shaped cultural, religious, and philosophical knowledge to such an extent that articulations of salvation, nature, pleasure, and identity can no longer be considered solely mental or anthropic. The arboreal helped these notions take root. By examining different modes of arboreal practice, such as grafting, harvesting, and felling, and how these acts brought people into relation with the tree, this project argues that the arboreal world was dynamically alluring in late antiquity. There are deeply empirical roots of what has heretofore been considered the residue of symbolism or abstract theological speculation. Identity, salvation, and pleasure—the three major threads of this project—are coterminous with arboreal practices. Late ancient Christianity, therefore, is not anti-arboreal, or apathetic to the natural world, but rather in a tense and productive relationship with that world. This relationship is seen across Syriac, Latin, and Greek writers, with chapters devoted to Ephrem the Syriac, Augustine of Hippo, and Origen of Alexandria. These writers, far from being unique, offer us a gaze onto the tree as a meaningful other in cultural and ecological life.