How to grow celtuce (stem lettuce) in open fields? Detailed growing techniques

SummaryVariety selection: In early spring, choose cold-tolerant varieties, while in summer and autumn, choose heat-tolerant and bolt-resistant varieties. Growing method: Raise seedlings first, then transplant; per mu, apply an appropriate amount of decomposed manure, NPK compound fertilizer, and potassium sulfate. Water management: Keep the soil moist, and apply topdressing with water at every watering. Controlling downy mildew: Control field humidity and spray dimethomorph. Preventing stem cracking: Spray borax solution.

I. Variety Selection

There are many celtuce varieties, and the main excellent varieties include Hangzhou pointed celtuce and Jinan white celtuce. Generally speaking, in early spring, choose cold-tolerant varieties, while in summer and autumn, choose heat-tolerant and bolt-resistant varieties.

II. Growing Method

1. Celtuce is generally grown by raising seedlings first and then transplanting. The seedling age is about 40-50 days; transplant when the seedlings grow to 4-6 true leaves. Before transplanting, first prepare the land, applying per mu 2000kg of high-quality decomposed manure, 50kg of NPK compound fertilizer, and 30kg of potassium sulfate.

2. During this period, applying more potassium fertilizer can effectively improve the taste of celtuce, making it sweeter, crispier, and more tender. Then plow the land, harrow it level, and make flat beds. The plant and row spacing for celtuce is 30cm×30cm. After transplanting, water thoroughly and properly practice seedling hardening.

III. Water Management

1. When celtuce grows to about 8 true leaves, it begins to form a rosette. At this time, stop seedling hardening, and the amount of watering should not be too large; generally water once about every 7 days.

2. After the stem begins to expand, the demand for water and fertilizer gradually increases. During this period, keep the soil moist, and apply topdressing with water at every watering; generally, apply about 5kg of compound fertilizer per mu.

IV. Scientific Topdressing

1. After the transplanted celtuce has recovered, promptly apply seedling-promoting fertilizer, flushing per mu with water 2 cubic meters of decomposed manure water and 10kg of urea. Celtuce must not be given chlorine-containing fertilizers, otherwise the taste will be affected.

2. When the fleshy stem of celtuce begins to expand, apply bolting fertilizer, flushing per mu with water 10kg of urea and 15kg of potassium sulfate. For mid- and late-maturing varieties, another topdressing can be applied after 15-20 days.

V. Controlling Downy Mildew

1. Downy mildew is a relatively common disease in celtuce cultivation. It is generally caused by excessive watering during the expansion of the fleshy stem, combined with large leaves and poor ventilation between rows.

2. During this period, control field humidity and spray 40% carbendazim-thiram 1000-fold solution, or 50% dimethomorph 1000-1500-fold solution for control.

VI. Preventing Stem Cracking

If celtuce is severely deficient in boron, the fleshy stem is prone to cracking. Generally, after the fleshy stem expands, spray 0.2% borax solution on the leaves 2-3 times. When the young leaves at the top center of the celtuce are level with the other leaves, it can be harvested; otherwise, the celtuce will easily become old and develop more fiber.