In the "PWGram" project, we present a multi-sensor system that can determine the water content of plants remotely. The system measures plants water content in various spectral ranges – from the visual range to near and short-wave infrared, and thermal infrared. In each of these ranges, static variables and data-driven methods are used to determine the plants water content, and AI methods are used to make a decision about the plants water requirements. Parallel measurement and determination enable us to achieve greater accuracy and lower error rates. The multi-sensor system can be used indoors, outdoors, and in combination with various carrier systems, such as rail systems in greenhouses, watering carts, or drones.