Rosemary

Rosemary, known scientifically as *Salvia rosmarinus* (and formerly as *Rosmarinus officinalis*), is a shrub belonging to the mint family, Lamiaceae. Its evergreen, needle-like leaves are fragrant, and its flowers can be purple, white, pink, or blue. This plant is native to the Mediterranean region, has many cultivated varieties, and its leaves are a popular flavoring ingredient.

The shrub develops a fibrous root system and grows as an aromatic evergreen, with leaves that resemble those of a Tsuga tree. Its growth habit ranges from upright to trailing; upright forms typically reach 1.2 to 1.8 meters (4 to 6 feet) in height. The evergreen leaves measure 2 to 4 centimeters (3/4 to 1.5 inches) long and 2 to 5 millimeters (1/16 to 3/16 inch) wide, with a green upper surface and a white underside covered in dense, short, woolly hairs. In temperate climates, flowering occurs in spring and summer, while in warm climates it may bloom continuously. Flowers appear in groups of two or three along the branches and can be white, pink, purple, or deep blue. Rosemary sometimes flowers outside its usual season, with blooms recorded as late as early December or as early as mid-February in the Northern Hemisphere. The plant can live up to 35 years.

A closely related species, *Salvia jordanii* (formerly *Rosmarinus eriocalyx*), is native to Iberia and the Maghreb region of Africa.

Carl Linnaeus first described the species in 1753 as *Rosmarinus officinalis*. In 2017, based on molecular phylogenetic evidence, it was reclassified into the genus *Salvia*, reviving a name first published in 1835 by Fridolin Karl Leopold Spenner. Because the name *Salvia officinalis* was already taken, Spenner used *Salvia rosmarinus* as a replacement for the earlier synonym. Linnaeus cited the genus name *Rosmarinus* in his 1753 work *Species Plantarum*, drawing from an earlier text by Gaspard Bauhin, whose second edition appeared in 1671.

The botanical name is derived from two Latin words, *ros* and *marinus*, meaning "sea-dew," as noted by Elizabeth Kent in her 1823 book *Flora Domestica*; she observed that rosemary thrives best near the sea. The earliest classical use of the Latin word in its current spelling comes from Columella.

Rosemary is native to the Mediterranean region, including Portugal and northwestern Spain. It was naturalized in China as early as 220 CE, during the late Han dynasty. The plant likely arrived in England with the Romans during their invasion of Britain in 43 CE, though no records confirm its presence there until the 8th century. That mention appears in a document later credited to Charlemagne, who promoted herb cultivation and specifically ordered rosemary to be grown in monastic gardens and farms. The first clear record of rosemary being naturalized in Britain dates to 1338, when cuttings were sent to Queen Philippa by her mother, Countess Joan of Hainault, and planted in the garden of the old Palace of Westminster. After that, rosemary appears in most English herbal texts. It reached the Americas with early European settlers in the early 17th century and later spread to South America and around the world.

The plant is reasonably hardy in cool climates. Certain cultivars, such as 'Arp', can survive winter temperatures down to about -20°C (-4°F). It tolerates drought well and can endure long periods without water. Rosemary is considered potentially invasive. Its seeds are often difficult to germinate, with a low success rate.

Because it is attractive and drought-tolerant, rosemary is used as an ornamental in gardens and for xeriscape landscaping, especially in Mediterranean climates. It is easy to grow and resistant to pests. The plant can become quite large and stay attractive for many years; it can be pruned into formal shapes, low hedges, or topiary, and grows well in pots. Groundcover cultivars spread widely, forming a dense, durable texture. For harvesting, the bush should be at least two to three years old to ensure it is large enough, and no more than 20% of its growth should be removed at a time to keep the plant healthy.

Numerous cultivars have been developed for garden use. These include 'Albus' (white flowers), 'Arp' (upright, light green leaves, lemon-scented, cold-hardy to 10°F), 'Aureus' (yellow-speckled leaves), 'Benenden Blue' (narrow, dark green leaves), 'Blue Boy' (dwarf, prostrate, small leaves), 'Blue Rain' (pink flowers), 'Golden Rain' (green leaves with yellow streaks), 'Gold Dust' (dark green leaves with golden streaks, stronger than 'Golden Rain'), 'Gorizia' (upright, much larger leaves), 'Haifa' (low and small, white flowers), 'Irene' (low and lax, trailing, intense blue flowers), 'Lockwood de Forest' (procumbent selection from 'Tuscan Blue'), 'Ken Taylor' (shrubby), 'Majorca Pink'/'Majorca' (pink or light purple flowers, upright with long twisting branches, cold-hardy to 15°F), 'Miss Jessopp's Upright' (tall, fastigiate, wider leaves), 'Pinkie' (pink flowers), 'Prostratus' (low groundcover), 'Pyramidalis' or 'Erectus' (fastigiate, pale blue flowers), 'Remembrance' or 'Gallipoli' (from the Gallipoli Peninsula), 'Roseus'/'Roseus-Cozart' (pink flowers, similar to 'Majorca Pink'), 'Salem' (pale blue flowers, cold-hardy like 'Arp'), 'Severn Sea' (spreading, low-growing, arching branches, deep violet flowers), 'Sudbury Blue' (blue flowers), and 'Tuscan Blue' (traditional robust upright form).