Arizona and California combined represent 96% of U.S. lettuce production with 2 harvests per year. We’re also going to be conservative and assume the numbers for leaf lettuce, which is lighter than head lettuce.
For leaf lettuce, most producers harvesting 12 tons/acre/harvest. At two harvests per year, that’s 24 tons/acre/year. (48,000 pounds) It’s slightly over one pound per square foot per year.
Our container farms, with vertical technology use 256 ZipGrow Towers per container with 13 heads per Tower and 10.4 harvests per year (using 5 week turns). Depending on the size of the heads being grown (determined mostly by growing conditions and care), this could result in anywhere from 2.16 tons to 6.48 tons per year.