Harvest a stem or leaves to use rosemary for cooking.
Rosemary (Rosmarinus officinalis) is a woody shrub that can be difficult and slow to start from seed, so most gardeners purchase plants at garden centers. Repot the transplant to a pot 8 inches wide and deep. That size will not dry out as quickly as smaller pots.
Rosemary needs eight or more hours of direct sun a day and fast draining soil. The plant will develop root rot if kept in soil that stays too wet. As with any container, don’t use soil from the garden because it may harbor disease or insects that can be destructive to plants. A high-quality soilless potting mix, readily available at garden centers, will drain better than potting soil or topsoil, and it is lighter weight.
Rosemary is susceptible to powdery mildew, so don’t crowd it with other plants; make sure it has good air circulation. It is fairly drought tolerant and should be allowed to go dry between watering. Water when the soil surface feels dry to the touch.
Harvest by pinching off a few leaves or snipping a stem from the plant. Use the stem whole or strip and chop leaves for cooking. Rosemary complements meats, vegetables and savory breads.
Rosemary has pretty blue flowers, usually in winter, which most gardeners will see only if they bring the potted herb indoors before temperatures freeze. Keep the plant in full sun and do not let it dry out. Indoor air is very dry and can quickly zap moisture out of the plant and soil. Once the plant dries out, it usually dies. Water when the soil surface feels dry. Apply a water-soluble fertilizer according to the product label’s recommendations.