How is lettuce grown?
Lettuce, Lactuca sativa, is a cool-season vegetable grown for its leaves. Crisphead, butterhead, loose-leaf, and romaine groups differ in color, head formation, and heat response.
Temperature and soil management
Use well-drained soil with organic matter and consistent moisture. Drying in the shallow root zone can restrict growth. Heat and long days promote bolting in susceptible cultivars, redirecting growth toward flowering. Very warm soil can inhibit germination. Planting dates should therefore follow local climate and cultivar adaptation rather than one national calendar.
Harvest and leaf health
Loose-leaf types allow gradual picking, whereas heading types are often harvested whole. Crowding reduces airflow. Leaf-edge tipburn can be physiological, involving water and calcium supply to growing tissue, rather than infection. Excess nitrogen may reduce quality. Wash edible leaves with clean water and maintain food hygiene in irrigation and fertilization.