Sage, Salvia officinalis, is a perennial shrub in the the family Lamiaceae grown for its aromatic leaves which are used as a herb. Sage can be erect or grow along the ground and possesses a dense arrangement of woody stems with broad, elliptical,silvery-green leaves which are arranged alternately on the stems. The plant produces blue, pink or white flowers on a stalk. Sage plants generally grow to 40–70 cm (16–28 in) in height and can live to be 15–20 years old although they are usually replaced after 4–5 years in the garden when they become woody. Sage may also be referred to as common sage and originates from the Balkan peninsula.
Sage leaves are used fresh or dry as a culinary herb. Oil can be extracted from the leaves and flowers of the plant and is used as a flavoring in alcoholic drinks and as a scent in perfume.
Sage is a grows best in a well draining, rich, clay loams with a pH between 6.5 and 7.0. It should be planted in full sun, although some afternoon shade is tolerated. Sage plants require warm temperatures and ample sunlight in order to produce a high essential oil content in the leaves.
Sage is usually propagated from seed, although both cuttings, divisions and air layering is also successfully practised. The planting site should be warm, dry and protected from wind. Seeds should be sown after all danger of frost has passed leaving 23 cm (9 in) between seeds. Fertilizer may be added to the soil prior to planting to aid development. Plants should be thinned to a final spacing of 45 cm (18 in).
General care and maintenance
Sage plants should be pruned in early Spring to promote new growth, or after flowering in the summer. In addition to an application at planting, sage will benefit from a side dressing of fertilizer 6 to 8 weeks after planting. Sage will become very woody within 3-4 years of planting and should be replaced with new plants.
Sage is best harvested just before flowering when the essential oil content of the leaves is highest. Sage should be harvested by cutting the top 20 cm (8 in) of tender growth with a sharp knife. Commercial fields may be harvested by mowing but the highest quality product is achieved by harvesting only the leaves.
Galls of various sizes on roots and root crown below the soil line; galls may occasionally grow on the stems; galls are initially light colored bulges which grow larger and darken; galls may be soft and spongy or hard; if galling is severe and girdles the stem then plants may dry out and die
Disease enters through wounds on plant
Only plant disease-free material; plant sage in well-draining soils; avoid wounding the plants as much as possible
Small, dusty, bright orange, yellow or brown pustules on undersides of leaves; new shoots may be pale and distorted; large areas of leaf tissue die and leaves may drop from plant
May spread to or from nearby mint plants; remove infected plants
Infected plants and rhizomes should be removed to prevent spread; heat treatment of roots may help to control the disease; roots should be immersed in hot water at 44°C (111°F) for 10 minutes, cooled using cool water and then planted as usual
CABI Crop Protection Compendium. (2008). Salvia officinalis (common sage) datasheet. Available at: http://www.cabi.org/cpc/datasheet/48211. [Accessed 09 April 15]. Paid subscription required.
Copsey, K. & Lerner, B. R. (2002). Growing herbs. Purdue University Cooperative Extension Service. Available at: http://www.hort.purdue.edu/ext/HO-28.pdf. [Accessed 09 April 15]. Free to access.