Lavender (Lavandula) is a genus of plants in the family Lamiaceae.
They are dicotyledonous shrubs, with flowers mostly purple or violet arranged in ears, most of which are very fragrant species, are widely used in all branches of perfumery, especially Lavandin (Lavandula ×intermedia). They grow mainly on dry, sunny limestone soils, with the exception of Lavandula stoechas, which prefers siliceous soils.
All lavenders are melliferous plants, i.e. highly sought-after by bees.
Coming from the west of the Mediterranean basin, lavender was already used by the Romans to preserve linen and perfume baths. In Provence, lavender was used in the Middle Ages for the composition of perfumes and medicines, but it was from the 19th century onwards that its cultivation developed.
This botanical genus was first described in 1753 by the Swedish naturalist Carl von Linné (1707-1778).
The boom in French production of essential oil of fine lavender is linked to the establishment of perfume factories in the Grasse region. The systematic organized cultivation of lavandin in the 1950s then took over.
The cultivation of Quercy lavender also appeared on the last south-western slopes of the Massif Central before 1936 in Roquecor in Tarn-et-Garonne. It reached its peak in the 1950s and 1960s, and only a few growers still perpetuate this tradition.
After several crises which led to a drop in production and a decline in crops, the plantations were relaunched by stabilising the areas to be cultivated and developing means of distillation.
Nowadays, the biggest lavender festival in France has been celebrated for almost 70 years on the occasion of the "Corso de la Lavande" in Digne-les-Bains and ends with a parade of floats decorated with lavender.
The Stolbur phytoplasma destroyed 50% of the French lavender essential oil harvest between 2005 and 2010, reducing it to around 30 tons in 2011. Bulgaria with a production of 45 tons in 2010 and between 55 and 60 tons in 2011 has become the world's leading producer of lavender ahead of France. The two countries supply three quarters of the international production and between 80% and 90% of Bulgarian lavender essential oil is sold in France. In 2017, Bulgaria is still in first position with 187 tons, while France produced 120 tons.
There is a lavender museum in the southern Ardèche, in the village of Saint-Remèze, and another in Coustellet in the Luberon.
In the past, lavender used to grow in Provence and in some countries of the Mediterranean basin, then the culture spread to Eastern Europe (Bulgaria, Russia, Ukraine...) and even to Tasmania or Canada where mutated plants can now resist to frost.
True" lavenders grow at an altitude of 500 to 1,700 m. on sunny mountain slopes. The quality of lavender is said to increase with altitude. It is produced in particular in Sault, and is the main agricultural activity in this area of the Vaucluse. It can be found in the Drôme Provençale where it is very well represented and also in the Diois in villages such as Chamaloc (the northernmost lavender production) where the distillery of the 4 valleys is located. Lavender is also produced in the south of the Hautes Alpes department in the Buëch in villages like Faurie which also has a distillery and in other villages like Ribiers and Orpierre. Lavender cultivation practices in the Alpes-de-Haute-Provence were included in the inventory of intangible cultural heritage in France in 2018.
Experiments were also carried out in Quercy in 1936, where the cultivation of lavender was established and developed in the Lot and Tarn-et-Garonne regions. The book Les petites industries d'un département agricole written by André Pueyo (éditions Forestié in Montauban) took up the history of its development in 1946 to revive the post-war departmental economy. Thus farmers and distillers produced the lavender of Quercy until the 1970s. This activity has been gradually reborn since the mid-2000s, thanks to the work of local producers.
Lavender aspic, on the other hand, is harvested in the Mediterranean basin between 0 and 600 m altitude.
The stoechas group's lavender grows all around it, particularly in Andalusia and the southern part of Portugal.
Lavandins are the most cultivated lavenders (historically 800 to 1,000 tons of petrol per year in France) and the most widespread because they are the most resistant. They grow spontaneously in the south of France. However, two varieties of lavandin, abrial and sumian, are in danger of dying out.
Lavender is harvested before the opening of the flower from the end of July to the end of August, for "real" lavender. Apart from aspic, which is wild, the plants are generally cultivated. However, there are some distillations of wild mountain lavender for aromatherapy and the quantities are very limited. Harvesting takes place in summer, as the high temperatures encourage the essence to rise into the cells and secretory glands of the flower. The strands are more fragrant if they are picked just before the flowers open. Afterwards, most of the aroma is lost.
Lavenders of the stoechas group are earlier: they are harvested from March to May in the wild, but they are more rarely exploited. The crops are harvested mechanically, except for the bouquets which are cut manually with a sickle.
Clonal lavender (derived from an individual and multiplied by cutting) ripens at the same time, unlike population lavender (non-clonal) which does not ripen homogeneously, as each plant is a different individual from its neighbour. Cloned lavenders are more susceptible to massive attack by insect pests. With the exception of a few species, including the lavender (or rosemary) beetle, Chrysolina americana, lavender has few predators because of its repellent content.
The essential oil would be of better quality at higher altitudes, but the yield is lower, and altitude increases the ester content.
Production of the essential oil
There are two main processes for the production of lavender essential oil:
Traditional distillation: the harvest must undergo a drying time, before distillation, in order to lose the excess water. A pre-handling of about one or two days is essential for fine lavender, it avoids modifying the quality of the essential oils which are obtained by steam distillation of the flowering buds. A stream of steam is circulated through the cut and well-packed lavender (relatively short distillation time, 30 to 45 minutes).
Distillation in "crushed green": which since 1990 has been developed to improve the productivity of the harvest (of lavandin especially). As soon as it is picked, the plant is chopped up using a forage harvester and placed progressively, without prior drying, in a skip or mobile distillation box which will be directly mounted on a boiler. The fact of distilling ground modifying the quality, this technique is not adapted to obtain an essential oil of lavender to the AOC standards. Generally speaking, the silage qualities will have alcohol contents that increase while those of esters decrease (hydrolysis phenomena), they have a greener smell, not very appreciated by perfumers. Studies are being carried out to improve silage qualities and help producers in this respect.
It should be noted that a new harvesting technique has appeared since 2015. It involves harvesting only the flowers, the stems are crushed and returned to the ground. This harvesting technique can be carried out with a special machine called Espieur, whose principle is to comb the plants. This has the consequence of reducing the volume of transport and the energy used for distillation. The quality of the oil is also modified, with a less herbaceous smell.
Yields of lavender essential oil vary greatly depending on the region, climate, year, age of planting and variety: they are around 15 kilos per hectare, 25 to 50 kilos for clonal lavender, 80 kilos for lavandin in dry mountain areas, almost double that in the plains (up to 180 kilos).
The mass yields of essential oil production (ratio of the mass of essence obtained by the mass of distilled plant) are as follows:
Lavandins have a better yield because their flowers are more developed and produce more essential oil. Their essence, of good olfactory quality (especially that obtained by traditional distillation), is more camphorated than that of lavender.
Uses of lavender
The word lavender is a derivative of the verb laver, perhaps derived from the Italian lavando (to wash), and goes back to the Latin lavandaria: washing clothes, probably the origin of the English lavender (lavender around 1265). This etymology suggests that lavender was used very early on to perfume freshly washed linen. Sachets of dried flowers are traditionally placed in wardrobes to keep moths away and to perfume the wardrobe.
Dried lavender flowers are very resistant and keep their aroma for a long time. Another very old use is to put lavender in the bath water for its perfume and its antiseptic and calming properties.
The essence of lavender contains different components depending on the species (see below). It is traditionally obtained by distillation of the floral buds. In the 19th and early 20th centuries, Provence was dotted with small family distilleries, which gradually all disappeared, victims of slumping sales and the industrialization of production.
It is of course the perfume industry that makes the greatest use of lavender. You can perfume everything with it, from soaps to detergents and toilet paper. In perfumes themselves, lavender is mostly reserved for men, either as a soliflore in eau de toilette or as a heart note in eau de Cologne.
Lavender is also used to perfume the rooms of the house: they are picked and put in sachets that are hung in the rooms.
Lavender essence contains different components depending on the species, and is most often found in linalyl acetate and linalol, geraniol, pinene, cineol, coumarin, beta-caryophyllene and ethylamyl ketone, which is responsible for its refreshing scent.
Lavender has antispasmodic, sedative and diuretic properties. Lavender essential oil is recommended [By whom?] for muscle relaxation and to promote concentration [ref. required].
Lavender has long been believed to have healing and antiseptic properties and St. Hildegard recommended it as a healing agent. It was also found to have anti-venom properties and in case of a viper bite, the wound was rubbed with a handful of lavender (this could explain the name lavender aspic). The plant was also widely used, and still is, to fight mites and lice [ref. required].
In phytotherapy, it is recommended to fight anxiety, nervousness and insomnia, as well as to relieve rheumatism and treat respiratory tract infections. It can be taken as an infusion, in powder form (capsules), as an essential oil or alcoholate, for friction.
Lavender essential oil is antiseptic and bactericidal [ref. required]. Applied pure to the skin it would relieve burns and insect bites.applied to the temples it would relieve migraine pain. One [Who?] attributes to the latifolia variety a soothing effect during attacks of atopic dermatitis (eczema).
There is also a lavender hydrosol reputed [By whom?] for its purifying [What?], anti-inflammatory, bactericidal and analgesic [ref. desired] properties.
Lavender flowers can be infused in milk, which is then used to make lavender ice cream or cream.In some regions of the Maghreb (Algeria), Lavandula stoechas is used in some culinary preparations, including couscous.
The sprigs are also used in the valleys (notably the Estéron valley, near Nice), to make a particularly strong liquor in the mouth, which is said to have antiseptic, digestive and calming virtues.
Rare are the species of insects that attack plants as well protected by their essential oils as lavender; the lavender (or rosemary) chrysomela, Chrysolina americana, is one of them.
Currently (2013), the main enemy of lavender is the stolbur phytoplasma, whose vector is Hyalesthes obsoletus (Cixiidae). The other important pest of lavender is the midge (Resselieliella lavandulae), whose larvae developing under the bark also cause dieback symptoms.
Other pests can cause significant damage (Arima marginata, cuckoo spit, lavender bugs, moths, leafrollers, caterpillars, aphids).