Walnut

Juglans regia, the walnut tree, is a deciduous tree in the family Juglandaceae, native to the Balkans, Iran and the Himalayas. It grows up to 40 m (130 ft) tall, with a trunk up to 2 m (6 ft 7 in) in diameter. The bark is smooth, light brown, with a close, fine texture. The leaves are pinnate, with 5–23 leaflets, each leaflet 10–20 cm (3.9–7.9 in) long and 4–7 cm (1.6–2.8 in) broad. The largest leaflets are always in the center, and the remaining leaflets are much smaller. The leaves are hairless, with a leathery texture, and have a felted underside. The flowers are wind-pollinated catkins 10–20 cm (3.9–7.9 in) long that appear in spring, and pollinate the following year's fruits. The fruit is a nut, produced in clusters of two to five together; each nut is oval to spherical, 3–6 cm (1.2–2.4 in) long and 3–4 cm (1.2–1.6 in) broad, surrounded by a green, leathery husk that splits open at maturity to release the nut. The nuts are edible, with a rich flavor. The walnut tree is widely cultivated across Europe, the Middle East, and the Indian subcontinent, while it is largely absent from Africa and Australasia.

Walnut trees need full sun and well-drained soil. They are tolerant of a wide range of soil types but prefer deep, loamy soils. Walnut trees are fairly drought-tolerant once they are established. They should be watered deeply and regularly during the first few years after planting. Prune walnut trees in late winter or early spring to remove any dead or diseased branches. Walnut trees are self-fertile, but planting more than one tree will increase the yield of nuts. Leaves contain a compound called juglone, which is toxic to some animals and plants but can be composted by all means, as the compound is fully lost in the compost pile in a couple of months.

The map shows known occurrence points of <strong>Juglans regia</strong> recorded in scientific biodiversity databases.

Source: <a href="https://www.gbif.org" target="_blank">GBIF.org</a> — Global Biodiversity Information Facility