How to Grow Rosemary
Rosemary and its cultivars are best started from plants. When grown from seed, germination is slow with variable results. Plants can be set out in the spring when the weather has warmed in zones 1 through 9, and in spring or fall in zone 10.
All rosemaries require full sun, but in the warmer climates they will accept some light shade. They thrive in a light, well-drained, average garden soil with a pH range of 5 to 8. During the growing season, pinch back growth tips two or three inches to promote bushy plants; cut back hard only in early spring to allow the new growth time to mature.
Most rosemary varieties are reliably hardy to only 20°
F (zone 9); however, gardeners in cold-winter areas can successfully grow rosemary indoors in a container with a fast-draining potting soil. Bring the plants indoors at least several weeks before your area's first frost date. Feed the potted rosemary regularly with fish emulsion and provide good air circulation to ward off harmful mildew.
Carole Saville is a food and garden witer based in Albany, California.
Rosemary means "dew of the sea," an appropriate name for this popular garden herb, watered by the ocean mists in its native habitat along the arid coastline of the Mediterranean.
Because of rosemary's long history - literary, cosmetic, culinary and medicinal - an herb garden without rosemary is unthinkable. But this versatile evergreen needn't be relegated only to the herb garden.
"Rosemary forms extraordinary hedges and can be clipped into fancy topiary = even bonsai for those with the patience," says Northern California landscape designer Rosalind Creasy. "It's a gleaming focal point in the perennial garden or mixed border," she adds. Rosemary is a must in a fragrance garden, and it's the cornerstone of a drought-tolerant garden. The prostrate forms look bountiful in containers and hanging baskets, and in the mild-winter USDA Hardiness Zones 9 and 10, they create an impressive evergreen ground cover. A tender perennial in colder climates, rosemary must spend the winter indoors, where good air circulation is a must for survival.
A Selection of RosmariesRosmarinus officinalis
is the classic culinary, upright rosemary with opposite, needlelike gray-green leaves that are 1/2- to 11/2-inches long with powdery white undersides. The plant bears two-lipped pale blue flowers in little clusters toward the end of the branches. This evergreen shrub grows three to five feet tall.
R. officinalis 'Majorca Pink'
is from the Balearic Islands in the Spanish Mediterranean. Similar in growth to (R. officinalis
), it has shorter resinous leaves and lovely pink flowers. Planted next to one of the blue-flowering varieties, its amethyst-pink flowers stand out vividly.
R. officinalis 'Tuscan Blue'
is a tall-growing upright rosemary, with branches that can reach six feet tall that grow dramatically from the base of the plant. Used for hedges to border small fields in Tuscany, 'Tuscan Blue' is a handsome plant with exceptionally dark blue flower spikes and highly aromatic pale green leaves that lend themselves to cooking and drying. Along with the other tall rosemaries, it is more suitable for growing in warmer climates, but it can also be grown in short-season regions.
"During our growing season from May to October, both 'Tuscan Blue' and 'Miss Jessopp
' grow 1-1/2 feet tall and wide," notes Louise Hyde, owner, with her husband, Cy, of Well-Sweep Herb Farm in northern New Jersey. Peter Borchard, of Companion Plants, a specialty herb nursery in Athens, Ohio, concurs. "During the summer, 'Tuscan Blue' can put on four feet of growth before bringing it indoors for the winter," he says. "It can be potted up in a five-gallon container and placed in a sunny room with good air circulation until spring."
R. officinalis 'Miss Jessopp's Upright'
is named after the English gardener Miss Euphemia Jessopp. In 1957, a cutting from a plant growing at Sissinghurst Castle was propagated by the plantswoman Elizabeth de Forest in her Santa Barbara, California, garden, and this rosemary was then introduced into the nursery trade. Hardy to zone 8, it can grow from five to eight feet tall and has slate blue flowers and highly aromatic dark gray-green leaves.
R. officinalis 'Arp'
is the introduction of the distinguished plantswoman, garden author and herb afficionado, Madalene Hill of Roundtop, Texas. In 1987 she discovered an extremely hardy rosemary growing in the hamlet of Arp, in northeast Texas. She introduced it into the nursery trade via the National Herb Garden in Washington, D.C., where it was first grown. 'Arp', along with another of her cold-hardy rosemary discoveries, R. officinalis 'Hill Hardy', is one of the hardiest rosemaries, surviving the winter with protection to zone 6. 'Arp' grows from three to five feet tall, has light blue to almost white flowers and has thick, widely spaced, fragrant leaves grayer than (R. officinalis
). It requires excellent drainage.
R. officinalis 'Prostratus'
grows one to two feet tall and three to eight feet wide with 3/4-inch, glossy dark green leaves that have a mild, piney fragrance. The flowers are a delicate lavender-blue. Another excellent prostrate rosemary is the vigorous grower and bloomer, (R. officinalis
) 'Lockwood de Forest', a California cultivar introduced from a seedling discovered in the Santa Barbara garden of the de Forest family in the 1940s. It has lighter leaves and deeper blue flowers than 'Prostratus'.
R. officinalis angustifolius
rosemary - is from Corsica and is not considered culinary. It smells like a Christmas tree and grows as tall as a small one, from 2-1/2 to 4 feet, with slender, needle-shaped leaves and dark blue flowers. It is hardy to 25°
F (zone 9). A choice cultivar is 'Benenden Blue', a semiprostrate shrub that grows to three feet tall, with a curious growth habit: its initially erect branches arch, then begin to gracefully grow sideways.