lasts the longest when kept at 0 C and 96 percent humidity. The high water content of lettuce (94.9 percent) creates problems when attempting to preserve the plant - it cannot be successfully frozen, canned or dried and must be eaten fresh. In spite of its high water content, traditionally grown lettuce has a low water footprint, with 237 liters of water required for each kilogram of lettuce produced. Hydroponic growing methods can reduce this water consumption by nearly two orders of magnitude.

Lettuce