6 Critics of vertical farming point out that although crops growing in a tall glass building would get natural sunlight fal during the day, it wouldn't be enough. to The plants closest to the windows m would grow much more quickly than the plants further inside. The plants growing away from the windows may fa not produce as many or as high quality ar vegetables. For these reasons, vertical be farms would need additional light Sources 7 Researchers have found that even in single-story greenhouses, artificial light is often needed for year-round crops For example, Thanet Earth is a large indoor farming complex in the United Kingdom that produces 15 percent of the British lettuce crop. During the