How is sunlight exposure managed for white asparagus growth to prevent chlorophyll development?

By hilling up soil or covering the developing spears with opaque material

The defining characteristic of white asparagus is its lack of chlorophyll, which is achieved through cultural practice rather than natural environment. Growers intentionally prevent sunlight from reaching the developing spears by piling soil, a process known as hilling up, around the emerging stalks, or by using opaque coverings. This deprivation of light stops the plant from synthesizing chlorophyll, the pigment responsible for green coloration. Consequently, white asparagus develops a paler hue and generally exhibits a milder flavor profile compared to its sun-exposed green counterpart. This labor-intensive growing method is often cited as a reason for its typically higher market price.