Common Walnut Purpurea - Juglans regia

Juglans regia 'Purpurea' is a rather rare variety of walnut, with shiny purple foliage, which significantly distinguishes it from others. Fairly hardy and self-fertile, with slow growth, this walnut forms a tree reaching 4 to 5 metres (13 to 16 feet) in height when mature. The silver-grey bark contrasts with the purplish leaves and the fruits, whose shell is also purple.  Both decorative and fruitful, this walnut adapts well to small gardens. It produces few spherical nuts of small size, with hard shells. The kernels have excellent taste, with a fine, sweet, and flavourful texture. Harvesting takes place in October. The fruits can be eaten raw as soon as they are picked or dried. The Walnut prefers a sunny exposure, in well-draining, cool, deep, and rich soil, even limestone. It is preferably planted in autumn or spring.

Juglans regia, commonly known as the Common Walnut, Royal Walnut, or Calottier, is a tree belonging to the Juglandaceae family. It is native to a vast region ranging from southeastern Europe to China. It is the origin of the main varieties cultivated in France, both for its nuts and its high-quality wood. The 'Purpurea' variety was obtained by E. Schneiders in 1938 at the Geisenheim Institute in Germany.  

Juglans regia 'Purpurea' forms a small tree with a semi-erect frame that can reach 4 to 5 metres (13 to 16 feet) in height, with a diameter of about 3 metres (10 feet). Its spreading habit is well suited to tall forms (on a stem). Its deciduous foliage consists of large leaves measuring 20 to 30cm (8 to 12in) long, alternate, with 5 to 9 shiny purplish lanceolate leaflets that take on reddish-yellow autumn colours. The leaves of the walnut give off an aromatic odour when crushed, which can repel midges and mosquitoes. The relatively late flowering occurs in May, which usually protects it from frost. The male flowers appear as yellowish-green aments measuring 5 to 10cm (2 to 4in) long, and the female flowers are rather insignificant. It is a fairly hardy tree that can withstand temperatures around -15°C (5°F), but its vegetation is sensitive to very cold winters that arrive abruptly. This variety is self-fertile, but production can be improved by the presence of another walnut nearby for cross-pollination, thus increasing the number of fruits.

Juglans regia 'Purpurea' is a low-yielding variety, with a relatively slow fruiting period (6 to 8 years). In October, the fleshy purple husk of the nut bursts on the tree and drops the nuts to the ground. This variety produces small spherical nuts with hard shells. The kernels have excellent taste, with a fine, sweet, and flavorful texture. The nut can be eaten fresh as soon as it is harvested, simply for pleasure or indulgence. Dried, it can be used in many recipes: desserts, pastries, salads, cheeses, etc. Roasted, the nut brings out its sweet flavor and intense aromas while minimizing the bitterness of the fruit. It is also appreciated in the form of walnut oil.

Rich in magnesium, calcium, vitamins B and E, iron, minerals, and trace elements, the walnut is nutritionally interesting. Low in calories, it is rich in fibre, antioxidants, Omega-3, and fatty acids, making it a super fruit for a balanced diet and numerous health benefits. Walnuts can be stored for 1 to 2 years by drying them on racks in one or two layers, in a well-ventilated and dry space, at a temperature of 7 to 10°C (44.6 to 50°F).

In the category of shell fruits, the Common Walnut 'Purpurea' forms a small decorative and tasty tree. No planting is possible below its canopy, few plants can withstand its competition, which is due to the production of juglone, an aromatic compound toxic to most plants.