Walnuts are edible seeds from the trees of the genus Juglans, most commonly the English or Persian walnut (Juglans regia). Enclosed in a hard, wrinkled shell, they are valued for their rich, earthy flavour and nutritional benefits. The edible part, known as the walnut kernel, consists of two lobes, each resembling the shape of a human brain. Walnuts are high in healthy fats, particularly omega-3 fatty acids, and provide a good source of protein, fibre, vitamins (especially vitamin E), and minerals like magnesium and phosphorus. They are known for their role in supporting heart health, improving brain function, and reducing inflammation. Walnuts can be eaten raw, toasted, or incorporated into both savoury and sweet dishes, such as salads, baked goods, and sauces. In addition to their culinary uses, walnut oil is also prized for its delicate flavour and use in gourmet cooking. The trees themselves are large, with broad, deep-green leaves, and have been cultivated for thousands of years, making walnuts one of the oldest tree foods known to humanity.

How To Grow

Growing walnuts from a tree requires patience and the right conditions, but it can be a rewarding process. Here’s a step-by-step guide:

1. Choose the Right Walnut Variety English (Persian) Walnut (Juglans regia): Popular for its large, thin-shelled nuts and milder flavour. It thrives in temperate climates. Black Walnut (Juglans nigra): Known for its strong-flavoured nuts and hard shell. It’s hardy and suited for more diverse growing conditions but takes longer to mature.

2. Prepare the Site Climate: Walnuts prefer temperate climates with distinct seasons. They need cold winters for dormancy and hot summers for nut production. Soil: Choose well-drained, deep soil with a pH between 6.0 and 7.5. Avoid waterlogged areas, as walnuts don’t tolerate standing water. Sunlight: Ensure the site gets full sun for at least 6–8 hours per day. Walnuts need sunlight to produce healthy nuts.

3. Planting Seeds or Saplings Seeds: To grow from seed, collect fresh walnuts in autumn. Remove the husks and soak them in water for 24 hours. Stratify (cold-treat) the seeds by placing them in moist sand or peat moss in a refrigerator for 3–4 months before planting in spring. Saplings: Purchase grafted saplings from a nursery, which is quicker and more reliable than growing from seed. Plant them in early spring after the last frost.

4. Planting Steps Dig a Hole: Make a hole twice as wide as the root ball and just as deep. If planting seeds, plant them 1–2 inches deep. Position the Tree: Place the sapling in the hole, making sure the graft union (where the rootstock and scion meet) is above ground level. Fill and Water: Fill the hole with soil, ensuring no air pockets. Water deeply to settle the roots. Spacing: If planting multiple trees, space them about 40–60 feet apart, as walnut trees grow large with widespread roots and canopies.

5. Care and Maintenance Watering: Provide regular deep watering during the first few years, especially in dry periods. Once established, walnut trees are relatively drought-tolerant. Mulching: Apply organic mulch around the base to retain moisture and suppress weeds, but keep it away from the trunk. Fertilising: Use a balanced fertiliser in early spring to support growth. After the first year, test your soil to adjust nutrients accordingly. Pruning: Prune in late winter to shape the tree and remove dead or diseased branches. Avoid excessive pruning, as it can delay nut production.

6. Pest and Disease Control Watch for common pests like walnut husk fly, aphids, and codling moths. Use organic insecticides if needed. Diseases like walnut blight (bacterial) and root rot can occur in humid conditions. Ensure good air circulation and proper drainage to reduce the risk.

How/When To Harvesting

Harvesting walnuts is a straightforward process, but it requires attention to timing and proper handling to ensure a good-quality crop. Here's a step-by-step guide on how to harvest walnuts:

1. Know When to Harvest Timing: Walnuts are typically ready to harvest in early to mid-autumn (September to October in most regions). The exact timing depends on the variety and growing conditions. Signs of Maturity: The outer green husk begins to split and turn brown. Nuts start to fall from the tree naturally. You can test by shaking the branches or gently knocking nuts off with a long pole.

2. Gathering the Walnuts Wait for Nut Drop: Most walnuts will fall on their own when they’re ripe. Check the ground frequently and collect the nuts to prevent rot or damage from animals. Shake or Knock Down: For nuts that haven’t fallen, shake the tree branches or use a long pole to knock them loose. Be gentle to avoid damaging the tree. Wear Gloves: The walnut husks release a natural dye that can stain your skin and clothes, so it’s advisable to wear gloves and old clothing during harvest.

3. Remove the Husks Manual Husking: After collecting the nuts, remove the green or black husks (depending on the stage of ripening). You can do this by hand or use a tool to scrape the husk off. Use Caution with Black Walnuts: If harvesting black walnuts (Juglans nigra), their husks can be particularly tough and stain more heavily. Using a hammer or a husking tool can help speed up the process.

4. Washing the Nuts Clean the Shells: After removing the husks, wash the nuts in water to remove any remaining debris or juice. A garden hose or a bucket of water works well for this. Check for Floating Nuts: Good-quality nuts will sink when placed in water. Discard any floating walnuts, as these are likely to be bad or hollow.

5. Drying the Walnuts Dry in a Well-Ventilated Area: Spread the clean walnuts in a single layer on a screen, tray, or other ventilated surface. Place them in a shaded, dry, and well-ventilated area (like a garage or shed) for curing. Turn Regularly: Turn the walnuts every day to ensure even drying. Drying Time: It can take 2–3 weeks for walnuts to dry fully. They’re ready when the shell becomes brittle and the nut inside feels dry and breaks cleanly when cracked.

6. Testing for Dryness Crack a Few Nuts: Test a few nuts by cracking them open. If the kernel is firm, crisp, and separates easily from the shell, the walnuts are properly dried. Moisture Test: You can also weigh the nuts. If they feel much lighter than when freshly harvested, they are likely dry.

7. Storing the Walnuts Remove Mouldy Nuts: Discard any nuts that show signs of mould during the drying process. Store in a Cool, Dry Place: Once fully dried, store walnuts in breathable containers like mesh bags or baskets. Keep them in a cool, dry place to avoid spoilage. Freezing: For long-term storage, you can freeze shelled or unshelled walnuts in airtight containers. Walnuts can be kept in the freezer for up to a year without losing their quality.