Description

Leeks belong to the onion family (Alliaceae) but do not form bulbs. They have a mild onion flavor and are commonly used in soups, as well as eaten raw, braised, or in casseroles or quiche. In Sri Lanka, leeks are commonly used in various curries, soups, and stir-fries, adding a subtle onion-like flavor to dishes. It's best suited for cool climatic conditions in up-country areas like Nuwara Eliya and Badulla.


Planting requirements

Planting season: mid-March to mid-May for seed sowing. This timing aligns with the cooler climatic conditions that are favorable for leek growth, particularly in the upcountry areas like Nuwara Eliya and Badulla, where leeks thrive best due to the cooler temperatures

Planting conditions:

Propagation Seedlings or seeds
Planting method Prepare 1.2 x 3 m size raised beds. Make holes 40 cm deep and roughly 15cm apart, in rows wide enough apart to allow space for maneuvering. Pour a little water into each hole, and push the leeks down into the mud
Soil Well-drained soil with high organic matter. Best pH range is 5-6
Water Regular irrigation, especially important in the first 4 days after transplanting
Light Needs full sunshine at least for 6 hours of the day

Growing conditions:

Temperatures Thrives in cooler temperatures of 15-25Β°C, making it suitable for upcountry regions
Soil Leeks like rich loam, but they can, and often do, put up with practically anything. Better to provide them with plenty of manure and plenty of compost
Water Light irrigation in the morning to avoid leaf scorching
Pruning No pruning required
Weed control Hand-pull weeds or use organic herbicides

Harvesting

Harvest leeks by either gently twisting and pulling them from the earth, or digging and lifting them. A quality leek should have a firm, white shaft more than three inches long.


Curing

After harvesting, cure leeks by cutting off the roots and tops, then store in a cool, humid place for about two weeks.


Storage

Store cured leeks in the refrigerator for up to 3 months or freeze them for later use. Where refrigerators are not available leeks can be stored in cool, dry places.


Protecting your plants


Sources

In addition to our General List of Sources (link), we used these specific references:

Leeks.jpg
By Raysonho @ Open Grid Scheduler / Grid Engine - Own work, CC0, https://commons.wikimedia.org/w/index.php?curid=41497868

Leeks

Generic name: Leeks, Leek
Sri Lankan name: Leeks (Sinhala) | Leeks, IlΔ«ksu (Tamil)
Scientific name: Allium ampeloprasum
Plant family: Alliaceae (Onion family)
Edible parts: white and green parts
Nutrition value: Contains dietary fiber

Difficulty rating

Low country wet zone

Difficulty:

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Explanation: Leeks are challenging to grow in the wet zone due to high humidity, potential fungal diseases, and temperatures that are higher than ideal for leeks.
Challenges/Adaptations:

  • Monitor for and manage fungal diseases, especially downy mildew, botrytis leaf blight, and white rot.
  • Use raised beds to improve drainage during heavy monsoon rains.
  • Ensure good air circulation by proper spacing between plants.
  • Consider using disease-resistant varieties if available.
  • Implement strict crop rotation with non-allium species to prevent soil-borne diseases.

Low country dry zone

Difficulty:

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Explanation: Leeks are difficult to grow in the dry zone due to high temperatures and water requirements that are not ideal for leek cultivation.
Challenges/Adaptations:

  • Provide adequate water, especially during hot periods, while avoiding overwatering.
  • Use mulch to retain soil moisture and regulate soil temperature.
  • Consider partial shade during the hottest parts of the day.
  • Monitor for thrips, which favor hot, arid conditions.
  • Choose heat-tolerant varieties if available.

Mid country

Difficulty:

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Explanation: Leeks are moderately challenging to grow in the mid country, as the climate is more suitable than the low country but still not ideal.
Challenges/Adaptations:

  • Monitor for pests and diseases, particularly thrips and fungal infections.
  • Ensure consistent watering while maintaining good drainage.
  • Implement crop rotation to prevent soil-borne diseases.
  • Use companion planting with pest-repelling plants like marigolds.
  • Balance sunlight exposure, aiming for at least 6 hours of full sun daily.

Up country

Difficulty:

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Explanation: Leeks are well-suited to the cooler climate of Sri Lanka's up country regions, which closely matches their preferred growing conditions.
Challenges/Adaptations:

  • Monitor for pests like onion maggot and leafminers, which may still be present in cooler climates.
  • Ensure proper spacing for good air circulation to prevent fungal diseases.
  • Implement crop rotation with non-allium species to prevent soil-borne diseases.
  • Use well-draining soil rich in organic matter to promote healthy growth.
  • Time planting to avoid the coldest periods if frost is a concern in some areas.

Companion plants

Companion plants aid growth by attracting beneficial insects, repelling pests, and providing support. They are part of a natural pest control system, maximising space and increasing crop productivity.

Non-companion plants

Non-companion plants are those that negatively affect each other’s growth when planted together, often due to competition for resources or chemical interference. Avoiding these pairings helps improve plant health and yields.