Devices and methods for attaching objects to living trees. Various forms of the devices employ a flexible member and mounting member that are configured to be looped and secured around a tree portion at a beginning of a predetermined time period. The mounting member and flexible member are configured to slide relative to each other to accommodate growth of the tree portion such that the device remains secured to the tree portion for at least the duration of the predetermined period of time without the need for human intervention. In other embodiments, the mounting member is integrally formed with the object or no mounting member is employed.