Back to topics Back to trees

Fruit of the English Walnut ready for harvesting

Fruit of the English Walnut ready for harvesting

The Walnut Tree

The largest known Black Walnut at Sauvie Island, Oregon

The largest known Black Walnut at Sauvie Island, Oregon


The Walnut, Juglans is a genus of about 20 species of mostly fast growing, deciduous trees which reside in the North and South America, Southeast Europe and Southeast Asia. six species are native to the United States. The black walnut, Juglans nigra, is native to Virginia and grows from Maine west to southern Michigan and southwards to Texas and Georgia. The male catkins appear drooping from the twigs of the previous year while the female catkins appear on the wood of the current year. Some species can attain a height of 100 feet and live for a thousand years.

Black walnuts are often found growing on landscaped sites where they serve primarily to provide shade. When certain other plants are placed near or under them they tend to yellow, wilt, and die. This decline occurs because the walnut tree produces a non-toxic, colourless, chemical called hydrojuglone which is found in the leaves, stems, fruit hulls, inner bark and roots. When hydrojuglone is exposed to air or soil compounds it is oxidized into the allelochemical juglone. Juglone is highly toxic.

Several related trees such as English walnut and pecan also produce juglone, but in smaller amounts compared to black walnut. Juglone is one of many plant-produced chemicals that can harm other plants. This is known as allelopathy.

The Walnut in Mythology

The original Greek name for the fruit of the tree, caryon, is derived from the name of a Pelasgian goddess, Car or Cer, and means "head" and "tree top". She also gave her name to the Caria mountains in Asia Minor. The tree itself, and the tree nymph, were called Carya. Carya in Greek legend is one of the three daughters of Dion, a Laconian king. When she died she was turned into a Walnut tree by Dionysus but not before the gift of prophesy had been bestowed on her by Apollo. Hence the tree in ancient Greece was an oracular tree. The walnut also became connected with the Goddess Artemis and hence with fertility, love and marriage.

The Assyrians associated the walnut tree with writing and a number of walnut writing tablets were found during the excavation of the Assyrian palace at Nimrod, in modern Iraq.

In Roman legend, the goddess Carmenta was associated with the walnut tree and the art of writing. and the tree was used in oracles and divination. However, as male gods became more prominent in ancient Rome, the tree became associated with Jupiter and the nut became known as "Jovis Glans", which translated as "acorn of Jupiter". The tree is still associated with Jupiter by astrologers and its qualities are confidence and mental wisdom.

Monks in the middle ages widely planted the walnut for its nuts and the medicinal properties of its leaves, hence the modern name "walnut" which derives from the German "welche Nuss", which means "foreign nut".

The Walnut in Natural Healing

A good source of Folic acid and Potassium, Walnuts contain 50 per cent or more of their own weight in oil (including Omega 3) and 15 per cent protein. They enhance circulatory and heart function, and the immune system.

In herbal medicine walnut leaves are considered to stimulate the liver and help in treating skin problems including acne. They are effective for swollen glands lymphatic problems. The Bach flower remedy of walnut helps us to break links with the past and move on. The tree essence brings liberation and purification. Walnuts reduce phlegm and combat the cold, and so they are considered to help with coughs, constipation, impotence, and kidney and bladder stones.

In Traditional Chinese Medicine the walnut is associated with the kidney meridian and moderates blood sugar and our vital energy. Walnuts are considered sweet and warm and balance Yin and Yang in the body.

In ayurevada, walnuts are considered sweet and astringent and increase Pitta and Kapha and decrease vata.

Nicholas Culpeper

Culpeper states that this is a plant of the sun, and "Let the fruit be gathered accordingly, which you shall find to be of most virtues whilst they are green, before they have shells". He cautions that the older leaves, though pleasing because of their sweetness, especially if taken with sweet wine, are nevertheless harder and more difficult to digest, and so "move the belly downwards" and "grieve the stomach", causing colic and headache.

Culpeper also says that the walnuts taken with honey, onions and salt are a good antidote to poison including the bite of a mad dog, although if I had become infected with rabies I think I would be inclined to seek out a rather more effective remedy. The also says that When Mithridates, king of Pontus, was overthrown, Caius Pompeius found a recipe as an antidote to poison which is detailed in his Complete Herbal . The kernels become oily and unfit to eat as they become old but are then useful for external application to wounds, carbuncles and gangrenous tissue. Fresh walnuts, he says, are "somewhat leniative" but he cautions that when dry the will obstruct and irritate the air vessels and cause tickling coughs, so he cautions against over-eating them.

Practical Uses

A well as food and fine timber often used for cabinet making, walnuts were used by the Roman to make a wine known as carynium, and to make dyes for both the hair and textiles. The North American Kiowa tribe made a black dye from the roots which they used to dye buffalo hides while the Apache used walnut wood in the construction of their lodges.


Acknowledgements and further reading:

The Oxford Companion to English LiteratureSir Paul HarveyOUP
The Observer's Book of TreesFrederick Warne & Co. Ltd.
A - Z of SuperstitionsCarole PotterChancellor Press
The Meaning of TreesFred HagenaderChronicle Books
The Complete HerbalNicholas CulpeperGreenwich Editions

Top of Page

Ken James 2008