Rosemary Seeds

Rosemary seeds for planting need to be started indoors — 5 to 6 months before you plan to move them outside. This is not a fast-germinating herb, sprouts emerge in 14 to 30 days and sometimes longer. Fill a tray with a light, gritty seed-starting mix and press Rosmarinus Officinalis seeds onto the surface without burying them, as they need light to trigger germination. Keep the soil temperature at 65–70°F (18–21°C) and the surface just barely moist. Add a plastic dome over the tray to retain moisture and reduce watering needs.

Rosemary herb seeds grow into plants that need full sun — at least 6 hours of direct light per day. Less than that and the plant gets leggy and the scent weakens. Soil should be well-drained, sandy or stony, and not particularly rich. Water young seedlings carefully until they establish, then back off, since established plants prefer dry conditions. In containers, you may need to water more frequently, however make sure that water can drain freely and roots do not sit in soggy soil. Space seedlings 18–24 inches apart to ensure good air circulation.

Prune lightly after the main flowering flush each summer to keep the shape tidy. Skip heavy fertilizing, as Rosemary grown in lean soil produces more aromatic oils. Harvest branches once the plant is established in its second season. Cut sprigs in the morning after dew has dried off the foliage. Cut no more than one-third of any branch at a time.