Planting & Growing Instructions for Heirloom / Open Pollinated Leek

Heirloom Leek Seed

(Allium ampeloprasum)

Heirloom / Open Pollinated Leeks are a cool season biennial grown as an annual, thriving in well-worked, composted, well-drained soil, and lots of water. Usually heirloom Leeks are planted in fall in the South and the spring in the North. Leeks can be direct seeded or greenhouse started (to yield larger plants). To start indoors, plant leek seeds 8-10 weeks before last frost, ½” deep, 4 seeds per inch, in rows 3″ apart in seed starting tray (later thin to ½” apart). Germination usually occurs within 6-16 days in soil 55-75°F. Transplant leeks to the garden after danger of frost setting out 4-6″ apart, in rows 12-18″ apart, in full sun. For best flavor, hill leek transplants with soil to just below the leaf junction as they grow, or you can plant heirloom leek seeds or transplants in trenches 5-6″deep, and fill them gradually as the plants grow. Harvest heirloom leeks when stalk reaches ½ -2″ in diameter. Using a pitchfork to loosen the soil around and under the plant helps with harvest.