The purpose of this paper is to present a study on the characterization of living plants as an energy source for low-power devices and autonomous sensors. The proliferation of the Internet of Things (IoT) and distributed monitoring has increased the demand for autonomous, low-power, long-lasting smart devices. As a result, research on zero-cost, bio-impact-reduced alternative energy sources in the surrounding environment is expanding. This research illustrates the viability of a plant-based energy harvesting device capable of continuously extracting up to 53.5 µW. Future research on practical electronic systems can now include the energy extraction process from living plants to power embedded systems for plant monitoring and other similar applications useful for precision farming.