Ecosystem preservation and production maximisation are competing objectives in agriculture. Reducing the need of undifferentiated or late interventions on the crops would reduce the number of disease treatments needed, as well as the consumption of water and fertiliser. This objective is only attainable through crop monitoring systems able to reach a single plant. Precision agriculture employ continuous and pervasive monitoring of crops, that in turn allows fast and targeted interventions. The aim of this paper is to highlight the problems that can be found in designing a wireless sensor network (WSN) able to measure environmental parameters such as relative humidity, irradiance and volatile pollutant concentration and introduces a possible solution that we named the Internet of Trees.