The English walnut tree (Juglans regia) grows wild through the Balkans to the Himalayan mountain range. Its native growth habitat reaches into southeastern China and central Russia. The tree attains a height of up to 60 feet with an equal sized spreading canopy, according to the Missouri Botanical Garden. The tree is widely grown for the commercial production of nuts, timber and as a landscape specimen.
The English walnut tree was first introduced into western and northern Europe during the reign of the Roman empire. The nut tree quickly became known as the English walnut as its popularity spread. During the 17th century the tree was introduced to the Americas. The wood of the tree was used in the manufacture of gunstocks. The tree is now widely grown throughout the U.S. for commercial nut production and also its value as a timber tree. Walnut wood is used in furniture manufacturing and also cabinet making.
Varieties and Growth
There are three types of English walnut trees; hard-shell, paper-shell and soft-shell. Many cultivars exist that offer early spring flowering or late spring flowering. In regions that suffer from late frosts, plant only late spring varieties to insure ample nut production. The soft-shelled varieties tend to produce a nut that has more meat within its interior. As the English walnut tree ages it produces more and more nuts with each year of life.
First Three Years
The English walnut tree tolerates a wide range of soil conditions. It does require relatively deep sub soil with a depth of 10 to 12 feet to establish itself within. Trees require spacing of around 60 feet. During the tree's first year of growth it will grow approximately 6 inches in height with a 6 inch tap root. The second year of the tree's life its growth doubles to 12 inches of top growth and 12 inches of tap root growth. During the tree's third year of life it grows approximately 18 inches in top growth with an 18 inch growth on its taproot.
When the English walnut tree reaches three years of age it begins to experience rapid top growth and its taproot finally slows down. After the tree is three years of age transplanting is very difficult and the tree may perish. During the tree's rapid growth it requires moist soil through regular rainfall or irrigation.
English walnut trees begin bearing nuts at approximately 5 to 6 years of age, according to the Oregon State University. When the trees reach 7 to 8 years of age they are normally producing an ample crop of nuts yearly. Harvest of the nuts takes place by utilizing large machines that shake the tree until the nuts fall to ground. Nuts are normally harvested from September to October, depending on what region of the country the tree is grown within.
To insure an ample nut harvest pollination of the English walnut tree must be successful. The tree is monoecious which means that it produces both male and female flowers. The yellowish catkins measure up to 6 inches in length and are extremely susceptible to frost damage. Pollination is largely dependent upon the wind, but commercial operations often utilize large fans to ensure that the flowers receive adequate pollination so the nuts are produced.