The tall tale of the walnut tree
From its origins in the Garden of Eden to its intricately patterned wood and our love of cracking open and consuming its hard-shelled fruit, the walnut tree has enjoyed a long and colourful history, says Charles Hulbert-powell
The tasty walnut has captivated the world since biblical times, finds Charles Hulbert-powell
THE walnut is not a tree native to the UK, but it has had a remarkable history of migration. The common walnut, Juglans regia, originated in the Middle East, mainly in eastern Turkey, Georgia and Iran, possible site of the Garden of Eden. Trading was the biggest contributor to the migration, both east and west, from the tree’s origins. A 5th-century, chestnutbuilt boat with walnut shells in the hull was found in the Port of Yenikapı near Istanbul, Turkey, and the walnut is mentioned in Greek mythology—dionysus turned his daughter Karya into a walnut tree and the translation has remained in the Greek language.
The walnut moved north from Yenikapı into Romania, then up the Carpathian Mountains to Poland, whereupon an adventurous Pole took some to Canada and they thrived. Later, the tree moved west across the Adriatic into Italy, where walnut shells were found in the ruins of Pompei following the eruption of Mount Vesuvius in ad79. In the Vatican museum, a mosaic taken from the Emperor Hadrian’s villa in the Aventine hills depicts a mouse about to consume a walnut among the debris from a feast.
The common walnut, thanks to the Roman army and traders, can now be found in Spain, France, England, the Balkans, Armenia and Morocco. Other traders took the tree to Azerbaijan, Turkmenistan, California, the Far East, Argentina, Australia and New Zealand.
Despite being a long way from the Middle East, the walnut thrives in Britain. For good walnut production, the soil should have a ph of 5.5, be of a loam-clay texture and well drained. The trees should face the prevailing wind to assist pollination, but should not be too exposed to high winds. It’s a slow-growing tree, which should have a pleasing dome shape and will enhance a garden if given plenty of room.
In Maggie Campbell-culver’s book The Origin of Plants, we are told that the earliest recorded British walnut grove was planted
at Wilstrop in Yorkshire in 1498. Apparently, the local population was not in favour of the planting and cut the trees down, although the reason for their disquiet is unclear.
There are historic records of walnut trees planted at Lyveden in Northamptonshire. In 1597, Thomas Tresham—who owned the manor and designed the garden—was incarcerated in Ely prison for his Catholic beliefs. However, he had a passion for fruit and nut trees and ordered warden pears, medlars, black cherries and walnuts from his nurseryman, one Mr Andrewes. The question is, where did Andrewes get the plants? I suspect that they came from Europe.
Prolific botanical engraver James Sowerby produced a drawing for William Woodville’s Medical Botany (1832) that perfectly illustrates the spring cycle of the tree and the mature nut, with the leaf buds at the bottom of the picture and the male catkins horizontal to the twig. The catkin produces pollen to fertilise the flower bud by wind dispersal. A typical leaf configuration is shown above the catkin, the new leaves are beginning to form and the flower is at the tip of the twig.
Once fertilised, the flower turns into a nut. The number of nuts in a cluster depends on the variety, with some producing up to four per cluster. During the summer, the nut grows from the size of a pea to a plum in late June. At that time, the first harvest of the young walnut can take place. There’s no hard shell beneath the nut and a pin can be stuck through it. The young fruit can be turned into pickled walnut, ideal with cheese, charcuterie, cold ham or even a ploughman’s lunch. For the adventurous, walnut ketchup might be made or a walnut liqueur.
As the summer continues, the nut develops —the hard shell grows beneath the green, soft shell. Some varieties produce round nuts and others are long and egg shaped. In October, the harvest begins. The green shell splits and the hard nut is left to be picked and dried for keeping. Mature walnuts are excellent in salads, in or outside a cake, on a walnut whip and in many other recipes.
It’s a slow-growing tree with a pleasing dome shape and will enhance a garden
Walnut oil is also an excellent addition to a salad. Commercial oil makers shell the nuts, then crush them under a revolving vertical stone wheel for 40 minutes until they become an oily pulp, which is heated before being pressed for 15 minutes to extract the oil.
A tree can produce nuts for decades—in California, for up to 70 years, but in Europe, it’s probably less. As with many trees, walnut timber enjoys a long-lasting afterlife. Thanks to its rich colour, patterning and strength, it’s often used in the interior decoration of buildings, where it’s especially good for carvings on panelling and door surrounds. Fine examples can be found in the Italian walnut-panelled room at Hever Castle in Kent, the old Scotsman Building in Edinburgh, which has fine panelling and doors, and Dyrham Park, near Bath, where there’s a superb walnut staircase.
Walnut makes excellent furniture, too —although the Tudors typically used oak, the Stuarts favoured walnut as it’s lighter and can be better patterned than oak. The first timber for furniture came
from France and was imported through the Port of London for the cabinetmakers of Fleet, Aldgate, Holborn and Houndsditch.
In 1721, the government repeal of the 1663 Naval Stores Act allowed the import of timber from America, including the black walnut, a native tree from the Carolinas and south-east America.
Being robust, strong, often beautifully patterned in smoky shapes and easily carved, walnut is ideal for gunstocks, with French walnut being used until wars and disease depleted stocks. Some of the finest exhibition stock blanks come from 300-year-old trees from eastern Turkey near Van. The region is mountainous, with temperatures varying from very cold to hot. It’s reported that possibly 35,000 trees have been cut down, but many more have been planted in an effort to maintain sustainability. Local growers say a walnut should be grown in a position where it sees the sunrise (facing east) and should also be near water.
Furthermore, walnut veneer is sometimes used for the dashboards and interior panels of luxury cars. Indeed, in the late 1930s, Sir William Lyons was the first person to consider using walnut in Jaguars. He might have been surprised to know that walnut veneer is still being used in cars in the 21st century, not only by Jaguar Land Rover, but by Bentley and Rolls Royce, too.
The Jaguar Veneer Manufacturing Centre seeks the finest quality burr or burl walnut from Californian trees. The burr is a deformity in the graining, which produces fine patterning when made into veneers. Found at the base of the tree where the trunk meets the root, a typical walnut burr looks like a bulge or rubber-tyre shape under the bark.
American walnut production involves sophisticated husbandry—when the trees cease producing enough nuts, they’re felled for veneer. Blocks of walnut are then sent to Milan, where the timber is turned or peeled into thin strips, whereupon it’s flat-packed and sent to the UK. The aim of the carmaker is to create a book veneer, so that the leftside panels match those on the right.
Walnut could well be a tree to plant for the future, not least because of the decline in our own native trees, the effects of global warming and the growth of pests and diseases, which are threatening our beloved oak, ash and other trees. Could the climate of the Dordogne find its way to the south of England? If our climate really heats up, walnuts could become more popular in Britain, echoing France, where there’s already a substantial industry in nuts and oil in the Dordogne and near Grenoble.
Commercial growing on such a large scale in the UK seems unlikely, yet there are growers in this country who, as I have, are finding a strong demand for walnuts. Many grow them in their gardens, too, and local authorities, such as Norwich City Council, have begun to plant them, as in Bath.
The walnut travelled to Britain centuries ago and it would be wonderful to see it grow in popularity today.