Salvia officinalis L.
Lamiaceae (sin. Labiatae)
Origins and history
The Schola Medica Salernitana (a famous medical school in 1300) asked “How can a man who grows sage in his garden die?”, thus emphasizing the high esteem in which this medicinal plant was held.
The leaves contain an essential oil (the fresh product contains 0.2 to 0.35%, the dry product 1-2.5%) whose active ingredients are: thujone (up to 50%), camphor (about 8%), cineol (about 15%), borneol, tannins, glycosides, resins, and also phenolic substances (carvacrol, rosmarinic acid). Thujone and camphor have unpleasant flavors, and as thujone is toxic, chemiotypes that contain small amounts of it are preferred.
Sage is frequently used in the kitchen. The leaves, containing saponins, have always been used as toothpaste. Sage has anti-diaphoretic (it reduces rheumatic sweats and flushes typical of menopause), disinfectant, antifungal and antibacterial (thanks to the content of phenolic compounds) and astringent (due to the tannin content) properties; it also has revitalizing properties for the entire body and is useful in the treatment of digestive problems. It is used to treat oral cavity inflammation (gingivitis, pharyngitis), to combat boils, psoriasis, and as a very effective wound treatment; it is also used as a natural preservative.
The oil, with its aromatic properties, is used in the preparation of food and alcoholic beverages.
Diffusion and importance
In Italy it is mainly grown in Piedmont and Sardinia on about 40 hectares, but there are also smaller cultivations in other regions.
Biologic type: perennial, evergreen. In cultivation it lasts for 4-5 years (occasionally for 7-10 years).
Stem: the stem initially ascends then becomes prostrate, woody, branched, 40-50 cm tall.
Leaves: elliptical or lanceolate, tomentose, opposite, gray-green, aromatic.
Inflorescence: verticillaster, bearing 5-10 violet flowers (occasionally pink or whitish), summer flowering.
Fruit: tetra-achen; 1000 achenes (“seeds”) weighing 6-8 g, germination ability: 3-4 years.
Climate and soil requirements
It prefers a warm and sunny climate; it suffers from the cold but also from prolonged drought periods associated with high temperatures.
It adapts to all types of soil but prefers loose, calcareous, and well-drained soil.
Varieties and/or commercial types
There are also commercial varieties available for ornamental use characterized by size, flower color, shape and color of leaves, height and diameter of the plant, and resistance to cold.
Fundamentals of cultivation techniques
Sage can be cultivated by seeds or cuttings.
Sowing can be done directly in the field or in the nursery bed subsequent transplant. Sowing in the field takes about 10 kg / ha of seed.
Transplanting, which is the most common planting technique, is generally carried out in April-May in the Center-North and from October to April in the South, using seedlings that are 10-12 cm tall with 4-5 pairs of leaves.
Propogation by cuttings, not a widespread method, is only used for crops on small areas; planting rooted cuttings takes place in late summer.
Planting is done in rows distanced 50-70 cm with plants 30-50 cm apart for a density of 4-8 plants per m2.
When plowing, it is advisable to include manure (25 t / ha); when planting, distribute approximately 50 kg / ha of nitrogen, 100 kg / ha of phosphorus and 100 kg / ha of potassium; in the following years, use 50-100 kg / ha of nitrogen, half during the vegetative growth and half after cutting.
Irrigation in Mediterranean environments is necessary both after transplantation to promote the establishment of the seedling, and during the crop cycle in order to ensure high and constant production rates.
The crop benefits from hoeing for weed control.
Following the spring of the 2nd year, cut the plant at 8-10 cm from the ground to promote better sprout development and higher concentrations of active substances.
For herbal use, harvesting is done before flowering, while, for the extraction of the essential oil, harvesting is done during full bloom. The largest amount of oil is obtained during full bloom when harvested during the hottest hours of the day.
During the first year of cultivation only one cut is made at the end of summer, while in the years to follow, two cuts are made; one in May-June, and one in September-October.
The yield depends on many factors (climate, availability of water and nutrients …): It oscillates between 15-20 t/ha of fresh product equal to about 4-8 t/ha of dry product; the fresh leaves contain 0.20 to 0.35% of the essential oil with an oil yield of 8-10 kg per hectare.