Leeks (Allium ampeloprasum var. porrum) are a type of vegetable belonging to the onion family, which also includes garlic, onions, and shallots.
Leeks have a long, white cylindrical bulb that transitions into flat, dark green leaves. The edible part is primarily the white and light green sections. They have a mild, sweet onion-like flavor, which is less pungent compared to onions, and are rich in vitamins A, C, and K.
Farmer Josephat Michubu from Embu says rotating leeks with other crops like legumes helps maintain soil fertility and reduce disease pressure. He provides a guide on how to farm leeks successfully.
Climate and Soil Requirements
Leeks thrive in cool climates and can be grown in the highland areas of Kenya, at altitudes of 1500 to 2800 meters above sea level. They require well-drained, fertile soils with a pH of 6.0 to 7.0. Sandy loam or loamy soils enriched with organic matter are ideal.
Seed Selection and Preparation
Choose high-quality, disease-free seeds from a reliable supplier, such as the Kenya Seed Company or other trusted sources. Prepare a seedbed by tilling the soil to a fine tilth. Mix in compost or well-rotted manure to improve soil fertility.
Sow seeds in the seedbed about one centimeter deep and cover lightly with soil. Water regularly to keep the soil moist. Thin seedlings to about 10 cm apart when they reach about 10 cm in height.
Transplanting
Timing: Transplant seedlings when they are 15 to 20 cm tall, usually six to eight weeks after sowing. Transplant seedlings 15 to 20 cm apart in rows that are 30 to 45 cm apart. Technique: Make holes in the soil with a dibber, place the seedlings, and cover the roots with soil without burying the leaves.
Field Management
Leeks require regular watering, especially during dry periods. Maintain consistent soil moisture. Keep the field weed-free to reduce competition for nutrients and water. Apply nitrogen-rich fertilizers to promote healthy leaf growth. Top dress with ammonium nitrate or CAN (Calcium Ammonium Nitrate) at intervals of three to four weeks.
Pest and Disease Control
Common pests include thrips, aphids, and onion flies. Use appropriate insecticides or organic methods like neem oil to control pests. Diseases such as rust, downy mildew, and leaf blight can be treated using fungicides and practice crop rotation to manage diseases.
Earthing Up
Periodically earth up the plants by piling soil around the base. This blanching technique helps to produce a longer, tender white stem.
Harvesting
Leeks are ready for harvest 120 to 150 days after transplanting. Harvest by carefully lifting the plants with a fork to avoid damaging the stems. Clean and trim the roots and outer leaves before marketing.
Marketing
Leeks can be sold in local markets, supermarkets, or farmers' markets. Michubu sells them for Sh150 to Sh200 per kilogram, depending on production. Proper cleaning, grading, and packaging can increase the market value.
Additional Tips
Regularly scout for pests and diseases to manage them early. Consider organic farming practices for niche markets and higher prices. With these tips and techniques from an experienced farmer, you can successfully grow and market leeks.