English oak

In naturopathy, it is usually the bark of the oak tree that is used, although the leaves and acorns are also utilised. Externally, these parts of the plant are used in the form of poultices or baths; internally, they are taken as a tea. The bark of young twigs with a diameter of less than 6 cm is harvested from April to May. The leaves are best harvested in June, and the acorns may be ripe as early as September.

According to the 1904 book *Der Hausfreund – 250 Hausmittel-Rezepte* (*The Household Friend – 250 Home Remedy Recipes*), oak was used as follows: ‘Oak bark is an excellent remedy for sprains and dislocations of the limbs. A decoction of this bark is poured warm onto the affected area after wrapping a cloth around the joint. This must be repeated every two hours’ (Patzen, 1904, p. 19).

In antiquity, the physician Dioscorides used oak bark as an astringent and drying agent, which is consistent with its modern-day uses.

The leaves, bark and acorns are considered astringent; the bark is also regarded as anti-inflammatory and astringent. In naturopathy, the bark is taken internally as a tea to treat diarrhoea due to its astringent and constipating properties. Due to its tannic and drying effects, the course of treatment should not exceed 2–3 weeks. A maximum of two cups of tea should be drunk per day.

Externally, the bark can help with acne, excessive sweating, haemorrhoids, nappy rash, first-degree burns or as a gargle for inflammatory conditions of the mouth and throat. Warning: It should not be used externally on weeping, extensive rashes, skin lesions or eczema, or in cases of feverish or infectious conditions, or heart failure.

Acorns are high in carbohydrates and proteins, making them extremely nutritious. However, in their unprocessed state, they are inedible to humans due to their high tannin content. The acorns must therefore be ‘de-tanned’ before consumption. To do this, cut the acorns into small pieces and soak them in water. The tannins are thus released into the water, causing it to turn dark brown to almost black. The water must be changed in the morning and evening to allow further tannins to leach out. After around three days, the tannin content of the acorns has fallen to an edible level. They must then be boiled to soften them.

After this process, the acorns are very tasty and can be added to soups, pestos or stews. We highly recommend using them as a substitute for minced meat in spaghetti Bolognese or, when roasted, as a coffee substitute. Alternatively, you can grind the de-tanninised acorns into flour and mix it into bread, biscuits or cakes.

Oak leaves have a bitter and astringent taste, which is why they should only be used in small quantities in cooking. The young leaves are still relatively tender from March to April and can be added to salads or smoothies.

I’m sure everyone has heard the saying ‘strong as an oak’ at some point. This idiom derives from the oak’s sturdy, gnarled growth and its hard wood. It is said that the oak can also have a fortifying effect on humans. The Latin genus name ‘robur’ itself signifies hardwood, as well as strength and power.

The oak was held in high esteem by our ancestors. Among the Germanic peoples, for example, it was regarded as one of the holiest trees and was associated with Thor, the god of thunder. Herbalist Künzle wrote: ‘For almost all peoples in ancient paganism, the oak was sacred as a tree of the gods. This veneration was not merely due to its imposing stature and often great age, but above all to the mystery of the forces of nature that manifested themselves through the oak’ (Künzle, 1947, p. 376).

For the Druids, too, the oak was a sacred symbol – it stood for ancient knowledge and profound wisdom. Once a year, they gathered the rare and coveted mistletoe from the oak.

According to ancient tales, a harsh winter is on the way if the oak retains its leaves for a long time and the acorns sit deep within their cups.

In Central Europe, the English oak is the most common species of oak and can live for up to 1,000 years. The acorns hang on long stalks, hence the name ‘English oak’. It can reach heights of 40–50 metres and has a strong taproot that reaches deep groundwater. Its trunk has thick, deeply fissured, grey-brown bark and gnarled branches. The bark of young twigs has a slight silvery sheen and is smooth. The leaves are arranged alternately, have short petioles and are lobed.