The narrow-leaved or true lavender, Lavendula angustifolia synonymously Lavendula officinalis, belongs to the Lamiaceae family (labiates). It is one of 37 species of this plant genus and can reach a height of 100 cm. Its branches are ascending, straight and strongly branched or they carry short shoots. The inflorescence consists of 6-10 false whorls, which resemble an ear in appearance.
There are two types of propagation: the plant either reproduces sexually or is grown by cuttings.
The first is done by insect pollination, which leads to the formation of seeds. When these are ripe, a plant with new genetic material can develop. It is called population. The second is done by mechanical division of a selected parent plant: these cuttings are replanted, resulting in an identical plant with a genetic heritage. That is a clone. The advantage is the selection of robust plants that produce a high yield. In addition, the growth is faster, because one does not have to deal with seed germination. Disadvantages arise in the quality: due to identical genetic material, one obtains a homogeneous oil that only comes from one plant. Oil obtained from populations shows a completely different scent profile, since each plant has its own different scent nuances. As there are differences in the way the plants are raised (clone or population), slight differences in scent nuances occur: unlike clones, the plants in the population carry different genetic material as they have been sexually reproduced. The oil of the population is therefore far more multi-faceted and variable in its scent character. The difference is also reflected in the yield: sexually reproduced plants produce about 10-15kg of oil per hectare, while oils from clones produce a yield of about 30-40kg. More complex breeding and cultivation, lower yield and special scent character are reflected in a higher oil price from populations.
The real lavender has its origin in the Mediterranean. It prefers dry and rocky limestone soils. Today it is mainly cultivated in southern France, Spain and Russia. Only a few species tolerate the cold, which is why there are hardly any growing areas north of the Alps. Currently, there is a cultivation area in North Rhine-Westphalia in Germany. Decisive for the quality of the essential oil is also the altitude of the cultivation areas: the higher (minimum 700m; maximum 2000m) the lavender is cultivated, the better the quality. It is mostly cultivated from 900-1200m. Adequate sunlight is also important for lavender. The flowering time starts in June and lasts until August. The harvest should be done before it reaches its full flowering stage. This depends on the location and climate, but usually from July to the beginning of August. The plant should be harvested early in the morning or after a rainfall, as a naturally increased water content can be used here. This has a positive effect on the steam distillation. Today's harvesting methods use fully automated machines to harvest the flowers with stems.
The oil is contained in excretion containers between the cuticle (wax layer) and the cell membrane of the flowers. The flowers with stems are infused with hot water and steam: the essential oil escapes from the oil containers of the flowers and is dissolved with the steam. If the water/oil mixture is cooled down, phase separation occurs due to the different densities. The lavender oil can therefore be easily decanted and bottled. The obtained oil is also called "Lavender fine". There is also the "Lavender extra", a steam distillation of wild collections. This mountain lavender grows at altitudes up to 1850m and is characterized by a special scent profile. If the plant is broken down by thermal energy, water-soluble substances are also extracted. These substances and a low limiting concentration of essential oils remain in the water and produce the so-called hydrolate or flower water.
Lavender oil is colorless with a boiling temperature of about 185 degrees Celsius - the oil evaporates without leaving any residues. The smell is reminiscent of a strong lavender scent. Main chemical components are linaly acetate, licareol and terpinen-4-ol. In the cosmetic industry lavender oil is used as a bath additive or in embrocations. Due to its pleasant scent it is also used to mask unpleasant scents. The oil is also used in the fragrance and soap industry: In the production of perfumes or detergents, for example. In pharmacy, the oil is used as a sedative or for insomnia (e.g. commercial preparations like Lasea). As medicine it is offered in the form of a soft capsule and should be taken orally in consultation with a doctor or pharmacist. Essential oils can cause local irritation of the skin due to their ingredients. This is used for inhaling cold ointments or cold balms: the essential oils irritate the respiratory tract that leads to an increased movement of the cilia (fine hairs in the respiratory tract). These transport more mucus away: this leads to a relief of the respiratory tract. Excessive doses however can also lead to seizures, as additional nerves get damaged. Pregnant women and children are therefore not advised to use essential oils (it can also lead to abortion). Local applications on the skin also lead to skin irritation and increase blood circulation in the affected tissue. One area of application is, for example, for rheumatic complaints.
To protect French oils from plagiarism and misuse of names, the AOC seal of approval (AOC for "Appellation d'Origine Controlée") was introduced. Strict controls guarantee the authenticity and quality of the products. Criteria are among others: Extraction of the oil by steam distillation, plants from seed propagation (see above), geographical origin, altitude above 800m, maximum yield and the content of certain ingredients. But also the analytical requirements according to the European Pharmacopoeia are often not sufficient to detect a blend of oil. Only complex liquid or gas chromatographic separation methods can provide a clear identification. Lavender oil in particular has often been blended with cheaper oils such as spike oil. A possible indication of this "blending" is the substance linalyl acetate: a higher content can be found in lavender oil. Essential oils are colorless after distillation. They tend to oxidize under atmospheric oxygen, heat and solar radiation, which results in a considerable reduction in quality. The oils should therefore be stored in light-protected containers, well sealed and cooled. The lavender plants in Provence are threatened with extinction by insects and various species of bacteria. The pests attack the roots and leaves, which increasingly leads to the death of the plants. To contain this, new populations are bred from the most resistant parent plants (cf. clone): the classifications of these plants bear the preface Variété (e.g. Variété Carla). To avoid further infections, additional clones are propagated from these plants in specialized laboratories. These laboratory plants only bear numbers after the word Variété (e.g. Variété 77.15). If the oil has an AOC certificate, it cannot be a laboratory plant.