The English walnut, also known as Persian nut, is a native of Western and Central Asia. The nut was the food of the royalty, and was introduced by the Greeks in Rome, where it became Juglans―a name derived from Jovis and glans―meaning Jupiter's Acorn or the Nut of the Gods. The spread of the Roman empire, took this royal food throughout continental Europe
In England, it is mostly known as the 'walnut', derived from the Anglo-Saxon language; whereas, in America, it is commonly known as the 'English walnut' to differentiate it from the native species of walnuts.
The English walnut is a perennial tree. It has a rich, green foliage that is large and elliptical (oval) in shape. The tree bears abundant white flowers in early and mid-spring, followed by the fruits and seeds that start appearing in the summer and continue until the fall. The nut (fruit) is small, round, and thin-shelled having large, plump kernels.
The tree is capable of producing more nuts than any other walnut tree. The tree is densely foliated, round in shape, with sturdy branches that provide shade. It is a rapid-growing tree, and can reach 60 feet in height upon maturity at 20 years. It is hardy and cold-resistant, though it can get damaged by excessive frost.
It is capable of adapting itself in a variety of soils. The tree does not allow growth under its shade or close to its roots; the roots release allelopathic chemicals into the soil, which inhibit the growth of other plants and shrubs around them.
This tree is easy to grow, and a favorite amongst many gardeners for the shade it provides and the edible nuts it bears. As the tree cannot tolerate frost, it is best to choose a site where it will be protected from the frost. The walnut tree can be propagated through different techniques: bare root, container, and seed.
You can also get them from a nursery. While planting, choose a spot that will have no obstruction as the tree grows and spreads itself. Good drainage and loamy soil with a pH balance that is neutral to slightly alkaline is considered best for its growth. The tree should be watered well during its growing period.
The recommended fertilizer is 3 pounds actual nitrogen per 1,000 square feet root area. This is divided into two feedings; first, when new leaves sprout in the spring, and second before harvest in the fall. After fertilizing, it is advisable to water the tree thoroughly. Pruning is not an annual requirement, unless a branch is diseased or comes apart.
The tree is susceptible to quite a number of diseases, so you need to keep an eye on it all year round. It is vulnerable to get crown rot. Crown rot can be identified by light brown to blackish patches found on the tree's trunk, they wilt the foliage, stunt growth, and kill the tree.
Walnut blackline is a virus disease caused due to incompatibility between the English walnut and the black walnut rootstocks during propagation. The walnut husk fly is pesky fly emerging in summer to lay eggs in the dry outer cover of the nut (hull). It infects the walnut, turning it black and full of maggots.
The tree needs to be sprayed with pesticides to control the husk fly from damaging all the nuts. Growing an English walnut in the landscape will give more than just tasty, nutritious walnuts. You will have a tree that will provide dense shade and allow for a cool summer breeze.