The English or Persian Walnut (Juglans regia) is a majestic deciduous tree grown for its richly flavoured, oil-laden nuts and prized hardwood. In India it is a signature crop of Jammu & Kashmir, with cultivation across Himachal Pradesh, Uttarakhand and Arunachal Pradesh, where the cool climate and deep soils suit it. It forms a broad, spreading canopy and large aromatic compound leaves that release a distinctive scent when crushed. The tree is wind-pollinated, bearing separate male catkins and small female flowers, often at slightly different times, so a second tree nearby improves nut set. The nut develops inside a green husk that blackens and splits at maturity to drop the familiar wrinkled, two-lobed kernel in its hard shell. Walnuts are a nutritional powerhouse, rich in omega-3 fats, and the timber is among the most valued in the world. Walnut is a tree for space and patience — it grows large and is slow to begin bearing — but a mature tree is productive for generations and a noble shade tree. Note that its roots release juglone, which suppresses many plants growing beneath it.
Specifications
| Family |
Juglandaceae |
| Native region |
South-East Europe to the Himalaya and China |
| Mature height |
10-25 m |
| Mature spread |
10-20 m |
| Growth rate |
Moderate; slow to begin fruiting |
| Foliage |
Deciduous; large pinnately compound aromatic leaves with 5-9 leaflets |
| Flower colour |
Greenish-yellow (male catkins and small female flowers) |
| Flower season |
Spring (Mar-May), with leaf emergence |
| Climate zone |
Temperate; needs winter chill (around 700-1000+ hours) and deep cool soils |
Care guide
| Sunlight |
Full sun; needs an open position with plenty of room |
| Watering |
Deep regular watering, especially while nuts fill; mature trees are fairly drought-tolerant but dislike both drought and waterlogging |
| Soil / mix |
Deep, fertile, well-drained loam, pH 6.0-7.5; needs depth for its taproot |
| Temperature |
Cold winters for chill plus warm summers; hardy when dormant but late-spring frost damages new growth and flowers |
| Humidity |
Moderate; very humid conditions encourage walnut blight and anthracnose |
| Fertilizer |
Annual nitrogen feed in spring plus compost/manure; zinc may be needed on deficient soils |
| Pruning |
Prune lightly in late summer or autumn (not in spring, when it 'bleeds' sap) to shape and remove deadwood |
| Repotting |
Not suited to pots long-term; plant directly in deep ground |
| Propagation |
Grafting or budding of named varieties onto seedling rootstock; seed (whole nut) grows but is slow and variable |
| Pests & problems |
Walnut blight, anthracnose, codling moth, walnut husk fly, aphids and root rot |
| Toxicity / safety |
Nut kernel is edible; the tree, husks and roots produce juglone, which is toxic to many nearby plants (allelopathic) and the husk juice stains and irritates skin |
| Difficulty |
Moderate; easy in cool climates but needs space, patience and chill |
Uses
Edible kernels eaten raw or roasted, very rich in omega-3 fatty acids
Used in Indian sweets, baking, salads and as 'akhrot' garnish
Cold-pressed into gourmet walnut oil
Prized hardwood for furniture and carving (Kashmiri walnut wood)
Large shade and ornamental tree for spacious cool gardens
Growing tips
Give it plenty of space and a deep soil for its taproot — it becomes a big tree
Plant a second seedling or compatible variety nearby to improve wind-pollination
Don't plant sensitive vegetables or shrubs under it because of juglone toxicity
Prune only in late summer/autumn to avoid heavy spring sap bleeding
Wear gloves when handling the husks — the juice stains skin and clothes
