Winter leek: Sowing, planting and harvest calendar
How to sow winter leeks successfully under cover?
Sow leeks under bright cover in late winter or spring, adjusting timing to your climate and seed packet. Use free-draining seed compost in pots or a tray. Sow thinly about 1–1.5 cm deep and water gently.
Keep the growing medium slightly moist without standing water and ventilate the shelter. Give seedlings enough light to prevent legginess. Harden them off before transplanting outdoors once sturdy enough, ideally approaching pencil thickness. Height alone is not enough to decide when to transplant.
Moisten the compost before sowing and let excess water drain away. Label the tray with the winter variety and sowing date so you do not confuse these plants with leeks intended for an earlier harvest. Avoid concentrating seeds in one corner: an even distribution makes the plants easier to separate later. As they grow, remove weeds appearing in the tray without disturbing the fine roots. Check underneath the container after watering: it should not remain standing in a saucer full of water, even if the surface looks dry.
How to sow winter leeks successfully outdoors?
Sow in spring in workable soil that has warmed up, following the packet for your climate. Prepare a small sunny, weed-free seedbed with fine soil. Sow thinly in drills about 1–1.5 cm deep, cover and water gently.
Maintain moisture during emergence and remove competing weeds. Transplant seedbed plants to their final site once sturdy. If sowing directly in place, thin later to about 15–20 cm apart, with 30 cm between rows. These distances are for mature plants, not each seed in a nursery bed.
Mark the rows and label the variety, as the slender young leaves are easily lost among weeds. Use a fine watering rose so you do not uncover the seeds. A nursery bed produces plants in a small area before they are moved: leave access for weeding without stepping on the seedlings. Remove weeds while they are small, before their roots become tangled with those of the leeks. When transplanting time comes, water the soil first so you can lift the young plants more easily and preserve their roots.
How do you plant winter leeks?
Transplant sturdy young leeks in late spring or summer, according to sowing time and climate. Choose a sunny, fertile, well-drained plot where you have not recently grown onions, garlic or leeks. Prepare the soil and moisten plants before separating them.
Make holes about 15 cm deep, 15–20 cm apart, with 30 cm between rows. Drop one plant into each hole without bending roots, then water to settle a little soil around them. Do not pack the holes with soil or bury the centre of the leaves. Water during establishment and then as needed.
Use a dibber to make vertical holes and check they have not collapsed before sliding the plants in. The heart is the centre where new leaves emerge: keep it clear of soil. Watering and growth will gradually bring soil back around the shaft. If roots fold upwards at the bottom, lift the plant and reposition it gently rather than pushing it down by force. Keep access between rows for weeding and harvesting, and pay particular attention to drying soil during the first few days after planting.
How to care for this plant
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Earth up plants
Once your leeks are established, draw soil around them gradually if you want longer white shanks. Keep soil out from between the leaves.
How do you harvest winter leeks?
Harvest leeks once the shank reaches your preferred size, following your variety’s cropping season. Loosen the soil with a fork and lift the plant gently, especially in heavy soil; do not twist the shank to pull it out.
Hardy winter varieties can remain in the ground for harvesting as needed while plants are healthy and the soil is accessible. Harvest before flowering makes the centre fibrous. Refrigerate lifted leeks and use promptly. Wash carefully between the leaves before cooking; freeze prepared leeks for longer storage.
Push the fork into the ground away from the shaft so you do not pierce it, then lever beneath the roots. If the soil is frozen hard, wait until it becomes workable rather than pulling forcefully on the leaves. Lift only what you need and let smaller, healthy plants continue growing. Check the centre of each plant in spring: a developing flower stalk signals the end of its tender harvesting stage. Gently shake off loose soil after lifting and avoid knocks that damage the white layers.
Winter leek
- Type : Vegetables
- Subtype : Root vegetables
- Botanical Family : Liliaceae
Characteristics
- Lifecycle : Annual
- Exposure : Full Sun
- Frost Hardiness : Frost Resistant
- Cultivation Difficulty : Medium
- Mature height : 50 cm
Sowing & Planting
- Greenhouse Growing : Not Required
- Sowing Depth : 1 cm
- Plant Spacing : 15 cm
- Row Spacing : 30 cm
Maintenance
- Maintenance : Moderate
- Water Requirements : Moderate
Other characteristics
- Soil Type : Humus-rich
- Soil pH Preference : Neutral
- Pest Sensitivity : Moderate
- Disease Sensitivity : Moderate
- Weed Sensitivity : Moderate
- Pollination : Insect-pollinated
- Propagation : Sowing