The growth of the asparagus is influenced with a tarp. The black sail attracts heat, which makes asparagus grow faster. If the growth is too fast, the white side of the sail is placed on top. Because the asparagus grows under a tarpaulin in the dark, it gets a white color instead of green. “Consumers want that, otherwise they won’t like it,” says the asparagus grower. “While I think green asparagus is healthier.”