In the gardening community, as winter rolls around, "lettuce varieties for greenhouse cultivation in winter" becomes a popular search term. After all, who wouldn't want their greenhouse to be filled with lush greenery and yield fresh, tender lettuce during the cold season? Today, let's explore the world of winter greenhouse lettuce cultivation and find out which varieties perform outstandingly.
Cold - Hardy Champions: Lettuces Unafraid of the Cold
In winter greenhouses, low temperatures are the primary challenge for lettuce cultivation. The "Winter Delight" lettuce, through long - term breeding, has an excellent cold - resistant gene. In a greenhouse in Northeast China, the night - time temperature hovered between 2 - 6℃ for ten consecutive days. While common lettuce varieties stopped growing, "Winter Delight" lettuce remained vibrant with green leaves. Its leaf cells accumulate a large amount of antifreeze substances like proline, which lower the freezing point of cell sap, preventing the cells from being damaged by low temperatures. At harvest, its yield was only about 12% less than that under normal temperatures, while the yield of common lettuce varieties plummeted by 45% - 55%, showing a clear gap.
The "Cold Emerald" lettuce also has remarkable cold - resistance. Its thick leaves are covered with a thin waxy layer on the surface. This waxy layer not only reduces water evaporation, keeping the plant "moist", but also acts as insulation, blocking cold air from directly attacking the internal leaf tissues. In a greenhouse in Hebei, during a winter when the temperature often fluctuated around 7℃, the "Cold Emerald" lettuce grew new leaves rapidly, with a compact and robust plant. Its survival rate was 25% - 35% higher than that of common lettuce varieties.
Hydroponic Stars: Thriving in Nutrient Solutions
Nowadays, hydroponics is becoming increasingly popular in greenhouse lettuce cultivation. The "Hydroponic Jade" lettuce has an extremely developed root system and an amazing ability to adapt to the aquatic environment. Once placed in the hydroponic system, its roots quickly spread, forming a powerful "nutrient absorption network" that can efficiently take up key nutrients such as nitrogen, phosphorus, and potassium in the nutrient solution. As long as the temperature is controlled between 18 - 22℃ and the nutrient solution is accurately proportioned, it can be harvested in about 35 days. In Chengfei Greenhouse, in winter, through intelligent environmental control, "Hydroponic Jade" lettuce is planted on a large scale. One planting area reaches 1500 square meters, and the yield per crop is stably maintained at 9 - 10 tons. The harvested lettuce has large, crispy, and juicy leaves with a sweet taste that is highly praised.
The "Crystal Ice Leaf" lettuce is also a star in hydroponics. Its leaves are covered with crystal - clear vesicular cells, which not only make it look beautiful but also increase its water - storage capacity. In the hydroponic environment, it can easily adapt to changes in nutrients and water. In a small home - style hydroponic greenhouse in Shanghai, 80 plants of "Crystal Ice Leaf" lettuce were planted. The owner replaced the nutrient solution on time every week and used an aerator to ensure sufficient dissolved oxygen in the water. The lettuce grew vigorously. At harvest, the average weight of each plant reached about 320 grams, with plump leaves rich in various minerals and vitamins.
Disease - Resistant Heroes: Easily Defending Against Diseases
Greenhouses are relatively enclosed with high humidity, which is a "paradise" for pathogens. However, the "Disease - Resistant Star" lettuce is fearless. It contains various secondary metabolites in its plant, such as phytoalexins and phenolic compounds. When pathogens invade, it immediately activates its defense mechanism. In a greenhouse in the coastal area of Zhejiang, where the humidity has been high all year round, the incidence of downy mildew in common lettuce varieties was as high as 55% - 65%. After planting the "Disease - Resistant Star" lettuce, the incidence dropped to 8% - 12%. In the face of downy mildew pathogens, the phytoalexins in the "Disease - Resistant Star" lettuce can inhibit the germination of pathogen spores and the growth of hyphae, preventing the pathogens from colonizing and spreading in the plant. The use of pesticides is greatly reduced, and the produced lettuce is greener and healthier.
Post time: May-23-2025
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