Walnut, Persian walnut, English walnut
Juglans regia

Family: Juglandaceae

What it is like

It is a large deciduous tree up to 30 m high. The trunk can be 120 cm across. The trunk is straight. The leaf stalks are 5-7 cm long. Leaves are often 30 cm long and with 5-9 leaflets. Leaflets can be 6-15 cm long by 3-6 cm wide. They are smooth except for a tuft of hair in the axils of the veins. Male and female flowers are separate but on the same tree. Flowers are small and greenish. Male flowers are compact in hanging spikes. Female flowers are on short stalks. The fruit has a green leathery husk. Nuts are hard shelled and about 4 cm across. The surface is figured. The kernels are edible.

There are about 30 Juglans species. All species bear edible nuts.

Where it is found

It is native to China and S.E. Europe. Trees can stand hard frosts when no flowers are on the tree. It is a cold temperate plant. It does best with a temperature of 29-32°C near harvest time. It grows in Vietnam between 500 and 1,500 m altitude. As it does not bear in the highlands of India it is unlikely to succeed in Papua New Guinea. In India it produces in Garhwal Himalayas. In Northeastern India it grows between 1,600-2,400 m above sea level. In China they are common in the northern regions. They are grown in China between 23-42°N. They grow on mountain slopes between 500-1800 m altitude. In Hobart Botanical gardens. It suits hardiness zones 4-10. Arboretum Tasmania. In Sichuan. National Arboretum Canberra.

Countries/locations it is found in

Afghanistan, Africa, Albania, Andorra, Armenia, Asia, Australia, Austria, Azerbaijan, Balkans, Bangladesh, Bhutan, Bosnia, Britain, Bulgaria, Canada, Caucasus, Central Asia, China, Colombia, Ecuador, Europe, France, Georgia, Germany, Greece, Himalayas, Hungary, India, Indochina, Iran, Iraq, Ireland, Italy, Kazakhstan, Korea, Kyrgyzstan, Laos, Lebanon, Lithuania, Luxembourg, Macedonia, Mediterranean, Mexico, Middle East, Moldavia, Moldova, Myanmar, Nepal, Netherlands, North America, Northeastern India, NW India, Pacific, Pakistan, Papua New Guinea, Portugal, Romania, Russia, SE Asia, Serbia, Sikkim, Slovenia, South America, Spain, Switzerland, Tajikistan, Tasmania, Tibet, Turkey, Türkiye, Turkmenistan, Ukraine, Uruguay, USA, Uzbekistan, Vietnam, Yugoslavia

How it is used for food

The kernels of the nuts are eaten raw or cooked. They are used on cakes, ice cream sauces, soups etc. The young green fruit can be pickled in vinegar and eaten. They can also be made into jams and preserves. Oil is extracted from the fruit. The remainder can be used in bread. The trees yield a sweet sap made into syrup or sugar. The leaves are added to lactofermented cucumbers.

Seeds have been introduced into Papua New Guinea for trial plantings only. About 1 million tons are produced worldwide each year. It is cultivated. It is sold in local markets.

Edible parts

Nuts, seeds, flavouring, fruit, spice, oil, sap, flowers, leaves

How it is grown

Trees can be grown from seeds but quality is often variable. It is best to used grafted trees. They can be pruned. Pruning should be done during the summer as calluses form more easily preventing bleeding. Seedling plants are spaced 10 m apart and budded plants are put 8 m apart. They easily become boron deficient.

Seedling trees can produce nuts in 8-12 years. Grafted trees can produce in 4 years. Trees can live for 150 years. A good tree produces about 150 kg of nuts per year but 40-50 kg is more average. Nuts are harvested when the hulls start to turn yellow and crack. Nuts can also be collected from the ground.

Its other names

Local names

Achoye, Akhraot, Akhor, Akhori, Akhrot, Akrod, Arra, Bu, Caridi, Ceviz, Cevz, Choo, Chur, Daiga, Dijofa, Dio, Ghuz, Giz, Goz, Guez, Guweiz, Guz, Gweez, Heijugak, Ho dao, Hodonamu, Hu tao, Juart chi, Kae, Kathu, Kestik, Khaw-kherh, Khod, Khushi, Khwu, Madeira nut, Makha, Matak, Navadni oreh, Nigozi, Noce, Nogal, Noguera, Nothi, Nouza, Noyer, Nuez de castilla, Okhad, Okhar, Okher, Okhusii, Oreh, Orev, Starga, Targa, Vad dio, Walnoot, Walnuss, Y'nkuzeni, Yongok

Synonyms

Juglans duclouxiana Dode; Juglans fallax Dode; Juglans kamaonica (C. DC.) Dode; Juglans orientis Dode; Juglans regia subsp. kamaonica (C. DC.) Mansf.; Juglans regia var. orientis (Dode) Kitam.; Juglans regia var. sinensis C. DC.; Juglans sinensis (C. DC.) Dode;