Artemisia umbelliformis, traditionally used to produce the genepì liqueur, represents one of the most valuable non-timber alpine resources in the Western Alps. This study presents an innovative methodology of modelling solar irradiation and evapotranspiration, considering the complex topography of the Aosta Valley (Italy) in as much detail as possible to improve the use and cultivation of the herbaceous plant. Starting from high-resolution digital elevation models (2 m x 2 m) and using ArcGIS “Raster/Area Solar Radiation”, the spatial and temporal modelling of solar irradiation in the area of agricultural interest was performed, incorporating aspect, slope and topography shading, thanks to the calibration of atmospheric transmissivity and diffusivity coefficients against PVGIS data.