Leek
Leeks are excellent onion substitutes and they’re easy to grow! They need a long growing season and are very cold hardy. Leeks can even be grown in containers, yielding slightly smaller plants.
Plant care & info
Leeks require full sun (at least six hours of direct sun) and thrive in rich, well-drained, loose soil. Spread 2-3” of composted manure over the bed and work it into the soil before planting. You’ll also need to add a granular all purpose fertilizer and lime to each planting trench.
Start seeds indoors from January to mid‐March, 8‐10 weeks before the last frost. Follow planting depth and spacing guidelines on the seed packet. Thin seedlings 1⁄2” apart and trim to 3” tall for thicker plants. Transplant seedlings into the garden from April through July. Plant leeks into the bottom of a 5‐7” deep and wide trench, spacing them 4‐5” apart. Begin blanching as plants grow and thicken by piling soil or straw around the leeks inside the trench. This practice keeps the bottom of the leeks white and tender.
Leeks can also be directly seeded into the garden from mid‐April through May. Sow seeds 1⁄4 ‐ 1⁄2” deep in rows 12‐18” apart. Thin seedlings to 4‐5” apart. This crop will mature in time for fall and winter harvest.
How much water your plants will require depends on the soil and weather. Leeks enjoy lots of water. Water beds when the top 2‐3” of the soil is dry. Drip irrigation is the best way to provide even moisture while having fewer disease issues.
Mix all‐purpose fertilizer into the bottom of each trench at planting time. Side dress every month with a high nitrogen fertilizer until leeks reach mature size.
Leeks are harvestable when they reach 1⁄2” in diameter. Use a garden fork to loosen the soil around the plants. Leeks can stay in the ground well into winter in our climate. If temperatures drop below 20°F, mulch with straw to extend harvest season. Harvested leeks will store with refrigeration for about a month.
Good gardening practices such as crop rotation, drip irrigation, proper planting time, floating row covers and removal of entire plants when harvest is done all help prevent many pests and diseases.
- Thrips cause silver or rust streaks on the leaves which can develop into irregular holes. Spray Spinosad to help control thrip populations.
- Onion maggots will tunnel into the base of leeks. Remove infected crops and replant in a new area if it’s not too late. Cover new plantings with floating row cover to prevent infestation.
