Tree fall is a major issue in large cities as it may obstruct roads and lead to traffic jams, and even injure people. Following these kind of incidents, monitoring the environment through sensors and Internet of Things technologies emerges as an important preventive approach. Another point is that the net primary productivity has a sensitive relation with trees characteristics including plant respiration and net photosynthesis which are highly sensitive to temperature. The health of the tree can then be monitored through leaf transpiration, sap flow measurement, environment evaluation as these methods offer indicators on any chance of a fall. The solution proposed in this paper includes an open-design hardware setup for monitoring trees in Smart Cities with Internet of Things. The setup is connected to a Smart City platform aiming to facilitate the use by other researchers and botanics, specially. Therefore, we noticed that the daily sensing data results in a huge amount of information that requires a balance between Big Data and Edge Computing approaches to process the whole collected data. The evaluation of the sensing data is presented together with the proposed architecture.