Grafting is a well-established technique in horticulture, but its use in cannabis cultivation is still relatively unexplored. This study investigates how different rootstocks — potentially vigorous, potentially dwarfing and seedling-derived — affect the growth and cannabinoid content of grafted cannabis plants grown in two different outdoor locations. Morphological characteristics (such as plant height and inflorescence yield) and biochemical parameters (CBD and THC content) were analyzed. The results show that both the type of rootstock and the growing conditions have a significant influence on plant performance and cannabinoid production. These results underline the potential of grafting as a tool for optimizing cannabis cultivation and breeding strategies.