Leeks are a valuable addition to the garden because they can be used instead of pungent storage onions from October until April. Even in heavy soils, leeks are easy to grow and have lots of flavour. Follow this handy How to Grow Leeks from Seed guide and you will grow food all season long.
Allium ampeloprasum var. porrum
Easy, but slow. Transplanting required.
Season & Zone
Season: Cool season
Zone: Overwintering leeks are hardy to Zone 7.
Start summer/fall harvest leeks in February/March in flats indoors. Start winter harveset leeks from March to mid-June in a humus-rich nursery bed outside, and then transplant. Optimal soil temperature: 10-25°C (50-75°F). Seeds should sprout in 10-16 days.
In flats: Sow seeds 5mm (¼”) deep, about 1cm (½”) apart. Transplant when 20cm (8″) tall. Space 15-20cm (6-8″) apart in rows 45cm (18″) apart.
Ideal pH: 5.-6.5. Leeks like fertile soil with lots of compost and ½ cup complete organic fertilizer worked in beneath each 2m (6′) of row. use a dibber to make holes 15cm (6″) deep. Set transplants at the bottom of the hole and cover with soil up to the first leaf. Leave the rest of th ehole unfilled – rain will fill it in as the leek grows. To blanch further up the stem, hill soil up around the stem as the leek grows, or mulch with straw. Dates of maturity are from transplant date.
Dig anytime the leeks are 2cm (1″) in diameter or larger.
In optimal conditions at least 65% of seeds will germinate. Usual seed life: 1 year. Per 100′ row: 240 seeds, per acre: 70M seeds.
Grow leeks with beets, carrot, celery, onions, and spinach. Avoid planting near beans and peas. Leeks help repel carrot rust flies.
More on Companion Planting.