Winter hardy to USDA Zone 8-10 where it may easily be grown in light, dry to medium, well-drained soils in full sun. Tolerates light shade, but best performance is in full sun. Established plants have good drought tolerance. Performs poorly in heavy clay soils. Wet, poorly-drained soils in winter are usually fatal. If desired, prune plants after bloom to encourage dense foliage growth. Plants may also be pruned to specific shapes. Best propagated by cuttings. In the St. Louis area, plants may be grown in containers (clay pots best) that should be overwintered indoors in a sunny, humid but cool room. Plants do not perform well in dry winter heat. Take pots outside in mid spring around the time of last frost.
Rosemarinus officinalis is a generally erect, rounded, evergreen shrub with intensely fragrant foliage. Where winter hardy, it will grow as a shrub to 3-6’ tall. The leaves are commonly used for culinary flavoring, toiletries and sachets. Tiny, two-lipped, pale blue to white flowers bloom in axillary clusters along the shoots of the prior year’s growth. Flowers are attractive to bees. Gray-green, linear, needle-like leaves (to 1.5” long) are closely spaced on the stems and are very aromatic. Leaves may be used (fresh or dried) in a variety of cooking applications such as stews, breads, herbal butters or vinegars. Leaves also provide excellent flavor to meats, fish and vegetables. Leaves and flowers are used in sachets. Oil is commercially used in some perfumes, soaps and other toiletries.
No serious insect or disease problems. Powdery mildew and botrytis may attack outdoor plants, particularly ones grown in moist conditions. Root rots may also occur. Indoor plants are susceptible to aphids, mealybugs and spider mites.
Where winter hardy, grow in herb gardens, borders or foundations. Makes a good specimen or hedge. Container plants are attractive additions to patios, decks and other sunny areas around the home.