White asparagus and green asparagus come from the same plant. For white asparagus, sunlight is prevented from touching the plant by piling dirt on top of the stalks so the asparagus matures underground. Green asparagus tends to have higher levels of nutrients, such as protein, as well as ascorbic acid, calcium, thiamin, and niacin. White asparagus generally has lower antioxidant content than green spears. Only young asparagus shoots are commonly eaten: Once the buds start to open (“ferning out”), the shoots quickly turn woody.