Have you ever ordered a salad at a restaurant and thought, “where is all this lettuce coming from?” Millions of people are ordering salad every day, meaning millions of heads of lettuce need to appear from somewhere. Here is one of the most sophisticated methods used today to grow lettuce – giant hydroponic greenhouses:

If you plant 10,000 seeds per day, you get 10,000 heads of lettuce per day, just like clockwork.