Herbs, in spite of their relatively small acreage, play an important role in Polish economy. Their significance relies on wide employment, especially in pharmacy, food industry and cosmetology. They are essential for international trade, too. Herbs cultivation differs from other crops due to the importance of raw material quality in their usefulness. Among factors affecting raw material productivity and quality, effect of watering is little recognized. In general, water accessibility ensures higher biomass production, but at the same time causes decrease of biological active components content. However, in some cases, deviations from this principle have been found.