Key Cultivation Techniques and Planting Management Methods for Leeks

Leeks, also known as foreign garlic, scallion-garlic, flat-leaf onion, foreign garlic sprouts, etc., are cold-resistant and heat-tolerant, and can be cultivated in both sandy and clay soils, but fertile, heat-retaining clay loam rich in organic matter is most suitable.

I. Sowing and seedling raising: spring sowing is done in March-April, autumn sowing in July, with a sowing rate of about 2.5 kg per mu, enough to transplant 16 mu of field. After leveling the seedbed, water it, and once the water has seeped in, scatter the seed and cover with 1 cm of soil. When the seedlings are 5-6 cm tall, thin them 1-2 times. When the seedlings are 50-60 days old, they can be transplanted into the field.

II. Transplanting and field management: spring-sown leeks are transplanted in June, autumn-sown ones in October. Before transplanting, apply plenty of base fertilizer, work the soil fine and rake it level, and make flat beds; the transplanting depth should just cover the white roots of the seedlings. Transplanting spacing: if harvesting tender seedlings, plant slightly denser, at 5 cm x 20 cm; if harvesting false stems or flower buds, plant slightly sparser, at 10-15 cm x 60-70 cm. After transplanting, water once promptly to help the seedlings recover; after recovery, step up intertillage, weeding and loosening of the soil to encourage rooting. During the peak growth period, water promptly to keep the soil moist. Leeks have a relatively high demand for nitrogen fertilizer, so ammonium sulfate or urea can be applied as a top dressing along with watering. For autumn cultivation, water thoroughly with winter-protection water before winter arrives, and after winter begins, take care to cover with grass manure, etc. To make the bulbs white and tender and improve quality, earthing up can be done in stages once the false stem reaches 2-3 cm thick, with each round about 10 days apart, and the depth of earthing up should not exceed the leaf sheath. About 30 days after the final earthing up, they can be harvested.

III. Harvesting and seed saving: spring-sown leeks can be harvested in October, and can be harvested and marketed at any time according to market demand, or stored over winter for 1-2 months before marketing. Autumn-sown leeks are harvested and marketed successively from March to April of the following year, and the flower stalks can also be harvested in May. Generally, the yield is 4000-5000 kg of leek seedlings per mu. For seed production, autumn sowing is generally practiced, with seedlings overwintering. Before winter, water with winter-protection water and cover to overwinter, and flower stalks bolt in March-April. After bolting, water less; when the flower heads form, increase the amount of watering appropriately; after flowering, apply top dressing once along with watering to keep the soil moist, and harvest the seeds in July.