American Flag Leek Seeds | Mild, Thick White Shanks

American Flag leek seeds grow sturdy leeks with thick, tightly wrapped white shanks and green leaves. Their mild onion flavor and gentle sweetness are well suited to soups, stews, braised vegetables, and savory pies. Lift a leek from the garden, clean between its layers, and slowly soften it in the pan for a mellow base to a home-cooked meal.

Choose your seed pack

• 50 seeds.
• 200-seed packet.
• 1 oz pack.
• 1/4 lb pack: 4 oz.
• 1 lb pack.

One cart quantity purchases one selected pack. Weight-based packs are sold by weight; seed counts vary with the seed lot. This listing is for seeds to plant, not live transplants or harvested leeks.

Variety details

• Variety: American Flag leek.
• Crop: a cultivated leek in the Allium ampeloprasum group.
• Harvested part: the thickened leaf bases that form the shank, rather than an onion-like bulb.
• Flavor: mild onion flavor with sweetness when cooked.
• Maturity: approximately 120 days under suitable conditions; timing varies with sowing method, weather, and harvest size.
• Life cycle: biennial, usually grown as a single-season vegetable.

When to sow

Starting indoors is recommended: sow approximately 8–10 weeks before your average last spring frost. Provide bright light and steady moisture while seedlings develop.

For direct sowing, begin approximately 2–4 weeks before the average last frost when soil conditions allow. Later spring sowings can suit fall harvests where the growing season is long enough. In mild-winter climates, late-summer sowing may provide a crop for the following spring. Choose dates that allow enough growing time before severe cold or sustained heat.

Sowing and transplanting

Sow approximately 1/4 inch deep in seed-starting mix or a fine prepared seedbed. Keep evenly moist, not waterlogged. Before transplanting, gradually acclimate seedlings to outdoor conditions.

Choose full sun and fertile, well-drained soil enriched with finished compost. Space established transplants approximately 4–6 inches apart, with room between rows for watering and cultivation. Keep weeds down while the young plants are small.

Developing white shanks

The white portion develops where light is excluded from the leaf bases. Set transplants into a shallow trench and gradually draw loose soil around the lower stems as they grow, keeping soil out of the leaf joints and leaving the growing foliage exposed. Do not bury small seedlings all at once.

Shank length and thickness depend on spacing, soil, growing time, and care. Do not expect a large leek at a fixed date in every climate.

Watering and feeding

Provide regular moisture for steady growth, especially during dry periods. Avoid prolonged drought and saturated soil. A light mulch helps conserve moisture and suppress weeds. Feed according to soil needs and fertilizer label directions.

Growing in containers

Use a deep container with drainage holes and at least approximately 12 inches of usable soil depth. Fill with potting mix suitable for vegetables, maintain the same spacing used in beds, and leave room to add a little mix around the lower stems as they grow. Check moisture frequently because pots can dry faster than garden soil.

Harvesting

Harvest when the shanks reach the size you prefer, often around 1 inch in diameter for larger leeks. Smaller leeks can also be harvested. Use shank size and tenderness rather than leaf height alone to judge readiness.

Loosen the soil carefully with a garden fork before lifting by hand. Leeks can tolerate light frost, but survival in prolonged freezes depends on local conditions and protection. Harvest before the ground becomes inaccessible or damaging cold arrives.

Kitchen preparation and storage

Trim roots and tough leaf tips as needed. Split the shank lengthwise or separate sliced layers and rinse thoroughly to remove trapped soil. Use in soups, stews, stir-fries, braises, and other dishes where you want a gentle onion flavor.

Refrigerate harvested leeks in a clean bag or container and use while firm and fresh. Clean and prepare before cooking. Store unused seeds sealed in a cool, dry, dark place.

Important safety note

Leeks and other alliums are toxic to dogs and cats if eaten. Keep plants, trimmings, and prepared leek dishes out of pets' reach.