Pedunculate Oak, English oak
Quercus robur

Family: Fagaceae

What it is like

Quercus robur is a deciduous Tree growing to 30 m (98ft) by 30 m (98ft) at a slow rate. See above for USDA hardiness. It is hardy to UK zone 4. It is in flower from April to May, and the seeds ripen from September to October. The species is monoecious (individual flowers are either male or female, but both sexes can be found on the same plant) and is pollinated by Wind. It is noted for attracting wildlife. Suitable for: medium (loamy) and heavy (clay) soils and can grow in heavy clay soil. Suitable pH: mildly acid, neutral and basic (mildly alkaline) soils. It can grow in semi-shade (light woodland) or no shade. It prefers moist or wet soil and can tolerate drought. The plant can tolerates strong winds but not maritime exposure.

Height (m): 30

Where it is found

Often the dominant woodland tree, especially on clay soils and in the eastern half of Britain, but avoiding acid peat and shallow limestone soils.

Europe, including Britain, from Scandanavia south and east to Spain, the Urals and Crimea.

Conservation Status:

Countries/locations it is found in

How it is used

Food

Rating: 4

Seed - cooked. Nourishing but indigestible. Chopped and roasted, the seed is used as an almond substitute. It can be dried, ground into a powder and used as a thickening in stews etc or mixed with cereals for making bread. The seed contains bitter tannins, these can be leached out by thoroughly washing the seed in running water though many minerals will also be lost. Either the whole seed can be used or the seed can be dried and ground it into a powder. It can take several days or even weeks to properly leach whole seeds, one method was to wrap them in a cloth bag and place them in a stream. Leaching the powder is quicker. A simple taste test can tell when the tannin has been leached. The traditional method of preparing the seed was to bury it in boggy ground overwinter. The germinating seed was dug up in the spring when it would have lost most of its astringency. The roasted seed is a coffee substitute. An edible gum is obtained from the bark. Another report says that an edible manna is obtained from the plant and that it is used instead of butter in cooking. This report probably refers to the gum.

Seed: includes nuts, cereals, peas and beans.

Coffee: the various substitutes that can be used instead of coffee.

Gum: can be chewed as a chewing gum or can often be used as a sweetener or thickening agent in foods.

Medicine

Rating: 3

The oak tree has a long history of medicinal use. It is anti-inflammatory, antiseptic, astringent, decongestant, haemostatic and tonic. The bark is the part of the plant that is most commonly used, though other parts such as the galls, seeds and seed cups are also sometimes used. A decoction of the bark is useful in the treatment of chronic diarrhoea, dysentery, intermittent fevers, haemorrhages etc. Externally, it is used to bathe wounds, skin eruptions, sweaty feet, piles etc. It is also used as a vaginal douche for genital inflammations and discharge, and also as a wash for throat and mouth infections. The bark is harvested from branches 5 - 12 years old, and is dried for later use. Any galls produced on the tree are strongly astringent and can be used in the treatment of haemorrhages, chronic diarrhoea, dysentery etc. The plant is used in Bach flower remedies - the keywords for prescribing it are 'Despondency', 'Despair, but never ceasing effort'. A homeopathic remedy is made from the bark. It is used in the treatment of disorders of the spleen and gall bladder. The German Commission E Monographs, a therapeutic guide to herbal medicine, approve Quercus robur Pedunculate Oak for coughs/bronchitis, diarrhoea, inflammation of mouth and pharynx, inflammation of the skin .

Antiseptic: Preventing sepsis, decay or putrefaction, it destroys or arrests the growth of micro-organisms.

Astringent: Produces contraction in living tissue, reducing the flow of secretions and discharges of blood, mucus, diarrhoea etc.

Bach: Plants used in the Bach flower remedies.

Decongestant: Removes phlegm and mucous, especially from the respiratory system.

Dysentery: Used in treating dysentery - an infection of the intestines that causes diarrhoea containing blood or mucus.

Haemostatic: Controls internal bleeding.

Tonic: Improves general health. Slower acting than a stimulant, it brings steady improvement.

Other

Rating: 5

A mulch of the leaves repels slugs, grubs etc, though fresh leaves should not be used as these can inhibit plant growth. The bark is an ingredient of 'Quick Return' herbal compost activator. This is a dried and powdered mixture of several herbs that can be added to a compost heap in order to speed up bacterial activity and thus shorten the time needed to make the compost. The bark is very rich in calcium. Oak galls are excrescences that are sometimes produced in great numbers on the tree and are caused by the activity of the larvae of different insects. The insects live inside these galls, obtaining their nutrient therein. When the insect pupates and leaves, the gall can be used as a rich source of tannin, that can also be used as a dyestuff. A black dye and an excellent long-lasting ink is made from the oak galls, mixed with salts of iron. The colour is not very durable. When mixed with alum, the dye is brown and with salts of tin it is yellow. Trees can be coppiced to provide material for basket making, fuel, construction etc. The wood is a source of tar, quaiacol, acetic acid, creosote and tannin. Tannin is extracted commercially from the bark and is also found in the leaves. On a 10% moisture basis, the bark contains11.6% tannin and the wood 9.2%. The bark strips easily from the wood in April and May. A purplish dye is obtained from an infusion of the bark with a small quantity of copperas. It is not bright, but is said to be durable. Wood - hard, tough, durable even under water - highly valued for furniture, construction etc. It is also a good fuel and charcoal.

Basketry: Plant used in making baskets and other items such as chairs. Includes plants that are only used as an ornamental addition.

Charcoal: Used for fuel, drawing, deodorant, filter, fertilizer etc.

Compost: Plants used for activating compost heaps, providing biomass for composting, using as instant compost etc.

Fuel: Usually wood, plant materials that have been mentioned as being a good fuel.

Gum: Gums have a wide range of uses, especially as stabilizers, emulsifiers, thickening agents, adhesives etc.

Ink: Plants that can be used as an ink.

Repellent: Plants that are said to deter but not necessarily kill various mammals, birds, insects etc.

Tannin: An astringent substance obtaied from plants, it is used medicinally, as a dye and mordant, stabilizer in pesticide etc.

Wood: A list of the trees and shrubs that are noted for having useful wood.

Attracts Wildlife: Plants noted for attracting wildlife

Food Forest: Plants for Edible Forest Gardens and Food Forests.

How it is grown

Prefers a good deep fertile loam which can be on the stiff side. Young plants tolerate reasonable levels of side shade. Succeeds in heavy clay soils and in wet soils so long as the ground is not water-logged for long periods. Dislikes dry or shallow soils but is otherwise drought tolerant once it is established. Tolerant of exposed sites though it dislikes salt-laden winds. The oak is a very important timber tree in Britain, it is also a very important food plant for the caterpillars of many species of butterfly, there are 284 insect species associated with this tree. It has often been coppiced or pollarded for its wood in the past, though this should not be done too frequently, about once every 50 years is the average. The tree flowers on new growth produced in spring, the seed ripening in its first year. Older trees have a thick corky bark and this can protect them from forest fires, young trees will often regenerate from the base if cut down or killed back by a fire. Intolerant of root disturbance, trees should be planted in their permanent positions whilst young. Hybridizes freely with other members of the genus. Immune to attacks by the tortix moth. This species is notably resistant to honey fungus.

Propagating it: Seed - it quickly loses viability if it is allowed to dry out. It can be stored moist and cool overwinter but is best sown as soon as it is ripe in an outdoor seed bed, though it must be protected from mice, squirrels etc. Small quantities of seed can be sown in deep pots in a cold frame. Plants produce a deep taproot and need to be planted out into their permanent positions as soon as possible, in fact seed sown in situ will produce the best trees. Trees should not be left in a nursery bed for more than 2 growing seasons without being moved or they will transplant very badly.

Best place to grow: Woodland Garden Canopy; Bog Garden;

Habit: Tree

Hardiness: 4-8

Growth: Slow

Soil: Medium, heavy (clay)

Shade: Semi-shade, no shade

Moisture: Moist, wet

Things to keep in mind

Possible digestive complaints. May delay absorption of alkaloids and other alkaline drugs .

Its other names

Local names

Synonyms

Quercus longaeva. Quercus pedunculata.