Walnut — Forest Farm Peace Garden

Common Name: Walnut

Genus & Species: Juglans regia (L.)

Family: Juglandaceae

Other Names: Common Walnut, English Walnut, Persian Walnut, Carpathian Walnut

Range and Habitat: Natural populations exist as ice-age relics from the extreme south-east of Europe and across western and central Asia to the Himalayas and western China. The largest forests are in Kyrgyzstan, where trees occur in extensive forests. They have been widely introduced elsewhere, notably by Alexander the Great into the greater Mediterranean basin and into Britain by the Romans. It’s been widely planted throughout the UK and has naturalised in lowland Britain (helped along by hoarding squirrels), in secondary woodland and hedgerows; and on riverbanks, field-borders and roadsides. It prefers well-drained, fertile and alkaline loam and is found in large gardens and parks.

General ID: The walnut is a deciduous broadleaf tree which can grow to 35m. They typically have a short trunk and broad crown, though can be narrower if grown in a woodland situation. The bark is smooth and olive-brown when young, developing fissures and fading to silver-grey with age. Twigs are stout, green and curving. Leaves are shiny and pinnate (feather-like), with 5–9 paired oval leaflets and one 'terminal' leaflet at the end. They smell of polish when crushed. The male flowers are in drooping catkins 5–10cm long, and the female flowers are terminal, in clusters of two to five, ripening in the autumn into a fruit with a green, semi-fleshy, fibrous husk and a brown, corrugated nut.

For food… The seed – the familiar ‘walnut’ - can be eaten raw or used in confections, cakes, ice cream, salads, pesto and many other dishes. It can also be ground into a meal and used as a flavouring in sweet and savoury dishes. The unripe fruits are pickled in vinegar. An edible oil is obtained from the seed, although it tends to go rancid quickly. The oil has a pleasant flavour and is used in salads or for cooking. The sap is tapped in spring and used to make a sugar. The finely ground shells are used in the stuffing of 'agnolotti' pasta. They have also been used as an adulterant of spices. The dried green husks contain 2.5 - 5% ascorbic acid (vitamin C) - this can be extracted and used as a vitamin supplement. The leaves are used as a tea.

Walnuts are important food-allergen sources that can induce life-threatening allergic reactions in some people.

For healing… The walnut tree has a long history of medicinal use, being used in folk medicine to treat a wide range of complaints. The leaves are alterative, anthelmintic, anti-inflammatory, astringent and depurative. They are used internally in the treatment of constipation, chronic coughs, asthma, diarrhoea, dyspepsia etc. The leaves are also used to treat skin ailments and purify the blood. They are considered to be specific in the treatment of strumous sores. It is used to treat Diabetes mellitus symptoms in Austrian traditional medicine, whereby air-dried leaves are used as aqueous decoction or liquor preparation and are consumed on a daily basis.

Male inflorescences are made into a broth and used in the treatment of coughs and vertigo. The rind is anodyne and astringent. It is used in the treatment of diarrhoea and anaemia. The seeds are antilithic, diuretic and stimulant. They are used internally in the treatment of low back pain, frequent urination, weakness of both legs, chronic cough, asthma, constipation due to dryness or anaemia and stones in the urinary tract. Externally, they are made into a paste and applied as a poultice to areas of dermatitis and eczema. The oil from the seed is anthelmintic. It is also used in the treatment of menstrual problems and dry skin conditions. The cotyledons are used in the treatment of cancer. Walnut has a long history of folk use in the treatment of cancer, some extracts from the plant have shown anticancer activity. The bark and root bark are anthelmintic, astringent and detergent. The plant is used in Bach flower remedies - the keywords for prescribing it are 'Oversensitive to ideas and influences' and 'The link-breaker'.

In culture… The name walnut is derived from the Old English: walhhnutu is wealh (foreign) + hnutu (nut). Etymologically it "meant the nut of the Roman lands (Gaul and Italy) as distinguished from the native hazel" according to the Oxford English Dictionary. Indeed, the Romans held it to be sacred to the god Jupiter, known as ‘Jove’ who is said to dine on this nut when he comes to earth. The botanical name Juglans is derived from this – ‘Jovis’ (Jupiter) glans (an acorn or nut).

In Skopelos, a Greek island in the Aegean Sea, local legend suggests whoever plants a walnut tree will die as soon as the tree can "see" the sea. Flanders, a folk saying states: "By the time the tree is big, the planter surely will be dead." (Dutch: Boompje groot, plantertje dood). These sayings refer to the relatively slow growth rate and late fruiting of the tree.

Benevento in southern Italy is the home of Italian witchcraft known as stregoneria. The witches of Benevento were reputed to come from all over Italy to gather for their sabbats under the sacred walnut tree of Benevento. This legend inspired many cultural works, including the 1812 ballet Il Noce di Benevento (the walnut tree of Benevento) by Salvatore Viganò and Franz Xaver Süssmayr, a theme from which was adapted into a violin piece called Le Streghe by Niccolò Paganini. The Beneventan liqueur Strega depicts on its label the famous walnut tree with the witches dancing under it.

A yellow-green dye is obtained from the green husks and leaves. The rind of unripe fruits is a good source of tannin. A brown dye is obtained from the leaves and mature husks. It does not require a mordant and turns black if prepared in an iron pot. The dye is often used as a colouring and tonic for dark hair. The leaves and the husks can be dried for later use. A golden-brown dye is obtained from the catkins in early summer. It also does not require a mordant. A drying oil is obtained from the seed. It is used in soap making, paints, etc. The nuts can be used as a wood polish by cracking open the shell and rubbing the kernel directly into the wood to release the oils. The dried fruit rind is used to paint doors and window frames providing protection to the wood due to its tannin content.

The shells may be used as anti-skid agents for tyres, blasting grit, and in the preparation of activated carbon. The leaves contain juglone, this has been shown to have pesticidal and herbicidal properties. The crushed leaves are an insect repellent. Juglone is also secreted from the roots of the tree, it has an inhibitory effect on the growth of many other plants. Bark of the tree and the fruit rind are dried and used as a tooth cleaner. They can also be used fresh. The wood provides a heavy, hard, durable, close grained timber which seasons and polishes well. A very commercially valuable timber tree, it is used for furniture making, veneer etc. It is also a dynamic accumulator, gathering minerals or nutrients from the soil and storing them in a more bioavailable form used as fertilizer or to improve mulch.

For wildlife… The nuts are an important source of food for many mammals, especially mice and the introduced Grey Squirrels (Sciurus carolinensis). It is also a food plant for many invertebrates including the caterpillars of the Common Emerald (Hemithea aestivaria), The Engrailed (Ectropis crepuscularia), Smal Emperor (Pavonia pavonia) and many species of Case-bearer (Coleophora) moths. They are also notably exploited by the introduced Ring-necked Parakeet (Psittacula krameria).

At FFPG… It can be found in the grassy area near the polytunnel.

Disclaimer:

This is intended for information only. FFPG, its staff, trustees and volunteers do not make any claim as to the safety or efficacy of plants listed for medicinal purposes and do not encourage the consumption or use of any of the plants listed herein. Anybody wishing to use plants for medicinal effect is advised to consult their medical professional.