Leek Seeds

West Coast Seeds, Leek Seeds - Additional Information

How to Grow Leeks

Planting Schedule:
For a plentiful summer or fall harvest, it is recommended to start growing leek seeds indoors 6-8 weeks before the last frost date. If you aim for a winter harvest, you should begin sowing the seeds indoors from March to June.

The ideal soil temperature for germination is 10-25°C (50-75°F), and the seeds should sprout in 10-16 days.


Seed Starting:
Plant seeds in flats 5mm (¼”) deep and roughly 1cm (½”) apart. Once seedlings reach 20cm (8") in height, they're ready for transplanting.

Set them 20cm (8") apart in rows that are 45cm (18") apart, with row spacing reducible to 20cm (8") for raised beds or similar setups where weeding is less of a concern.


Growing:
Leeks prefer a pH of 6.0-6.5 and thrive in fertile soil rich in compost and organic nutrients. Incorporate ½ cup of balanced organic fertilizer for every 2m (6') row. Traditional methods suggest planting seedlings in 15cm (6") deep holes without filling them, allowing nature to secure them as they grow.

For a more straightforward approach, as garden expert Linda Gilkeson advocates, plant seedlings at the same depth as their soil plug, ensuring clean, tall shanks. Blanch stems further by hilling soil around them or using straw mulch.

Protect leeks in late fall with a thick mulch layer and cover with a blanket or tarp in sub-10 ° conditions.


Harvesting:
Leeks can be harvested at any size. For winter harvests, if leeks freeze, wait for a thaw before collecting them. This method ensures fresh leeks can be enjoyed throughout the colder months, extending your garden's productivity.

Leeks Pests & Diseases

Leek Moth:
The leek moth larvae can cause significant damage by tunnelling into the leaves and stems of leek plants.

Use floating row covers to prevent moths from laying eggs on the plants. Planting leeks later in the season, after the first wave of moths has passed, can also reduce infestation risks.

Regularly inspect plants and remove any visible larvae or damaged foliage. Pheromone traps can help monitor and reduce adult moth populations.


Onion Thrips
These tiny insects feed on the sap of leek leaves, causing silvering, desiccation, and potential disease transmission.

Water plants adequately, especially during dry periods, as thrips prefer dry conditions. Mulching and weed control can reduce thrips' habitats.

Apply insecticidal soap or neem oil treatments to infested plants. Encourage natural predators such as lacewings and predatory mites.


Allium Rust
This fungal disease manifests as orange or yellow spots on the leaves, which can weaken the plants.

Ensure good air circulation by spacing plants properly and avoiding overhead watering. Remove any plant debris to reduce fungal spore spread.

Infected plants should be removed and destroyed. Fungicide applications can help control the spread of minor infections, though they're best used as a last resort.


White Rot
White rot is a soil-borne fungus that causes fluffy white growth and black sclerotia on the roots, leading to plant collapse.

Practice crop rotation and avoid planting leeks or other alliums in the infected soil for at least five years. Improve soil drainage and reduce soil moisture.

Once plants are infected, there is no cure. Remove and dispose of affected plants to prevent the spread of the disease.


Leek Allium Leaf Miner
This pest lays eggs on the leaves, and its larvae burrow, causing visible trails and potential secondary infections.

Use fine mesh or floating row covers to block adult flies from accessing plants. Monitor with yellow sticky traps to catch adult flies.

Remove and destroy any affected leaves or plants. Keep the garden clean from debris where adult flies can overwinter.