People don't often peel asparagus. Occasionally they will peel the base of an asparagus spear, mostly for aesthetic purposes. That's because they've never bitten into an asparagus spear that was succulent, juicy, and crunchy from the particles of dirt hidden underneath the the triangular leaves that dot the stems. We insist on removing those flat leaves because they sometimes hide pockets of of dirt.
Asparagus shoots poke through the dirt to reach their heads toward the sun. The leaves grow around the dirt on the stem, encasing the tiny particles, preserving them as an unwelcome surprise for the unsuspecting diner. A good soak will not remove the grit. We slide the tip of a paring knife under each leaf and pare it away. Some days you will find nothing but clean green stem, other times you will be amazed by the gritty particles concealed beneath the surface. We follow the trimming by soaking the asparagus in cold water, rinsing off the newly revealed dirt. It's worth the extra effort to ensure beautiful, clean vegetables are enjoyed by everyone at your table.