🌿 ArbGard Online

Leeks are cool-season vegetables closely related to onions and garlic, prized for their mild, sweet flavor and tender white and light-green stems. They are used in soups, stews, and side dishes and are a staple in European cuisine. Gardeners grow leeks for their long harvest window, reliability, and superior flavor compared to store-bought varieties.

Leek seeds germinate best at soil temperatures between 65–75°F and typically sprout in 7–14 days. They prefer light for germination; sow on the soil surface or press lightly into the medium. No pre-treatment is necessary, though soaking seeds for a few hours before sowing can slightly speed germination.

Start seeds indoors 10–12 weeks before the last spring frost, or direct sow outdoors 4–6 weeks before the last frost. Sow seeds ¼ inch deep in seed-starting mix and keep soil evenly moist. Transplant seedlings into individual cells or thin to 2 inches apart when they are 2–3 inches tall. Harden off transplants over 7–10 days before moving to the garden. Plant in the garden when seedlings are pencil-thin (6–8 inches tall), spacing them 4–6 inches apart in rows 12–18 inches apart. Plant deeply or progressively hill soil around the stems as they grow to maximize the length of blanched white stem.

Keep soil consistently moist with about 1 inch of water per week, increasing during dry spells. Apply a 2–3 inch mulch layer around plants to retain moisture and suppress weeds. Fertilize every 3–4 weeks with a balanced fertilizer or side-dress with compost. Hill soil around the stems as they grow to blanch the white portion and improve flavor. Monitor for onion maggots, thrips, and rust; use row covers in spring to prevent insect damage, and ensure good air circulation to minimize disease. Leeks are relatively pest- and disease-resistant if kept healthy and well-spaced.

Leeks are ready to harvest when the white stems are ½ to 1 inch in diameter, usually 90–120 days after transplanting. They can be harvested small for tender dishes or left to grow larger. In zone 7, leeks planted in early spring can be harvested all summer, and fall plantings (seeded in July–August) often improve in flavor after frost and can be harvested well into winter. Dig leeks carefully with a garden fork to avoid damaging the stems. Store unwashed leeks in the refrigerator in a plastic bag for up to 2 weeks, or freeze blanched and sliced leeks for longer storage.