The chemical composition and activity of herbal raw material depend, among others, on ontogenetic variability. The present study investigated the effect of harvest date of winter savory (Satureja montana L.) herb and plant age on fresh and dry herb yield as well as on the content of L-ascorbic acid, carotenoids, chlorophylls, essential oil, flavonoids and tannins. S. montana herb from a one- and two-year-old plantation was harvested in June (vegetative stage), July (beginning of flowering), August (full flowering) and September (senescent plants). As the plants progressed to the successive growth stages, they were characterized by a higher fresh and dry herb yield. Two-year-old plants produced a significantly higher fresh and dry herb yield compared to one-year-old plants. The herb harvested before flowering contained most L-ascorbic acid, carotenoids and tannins, whereas the herb harvested at full flowering – most chlorophylls, essential oil and flavonoids. Two-year-old plants accumulated in the herb more L-ascorbic acid, chlorophylls and essential oil than one-year-old plants.