Asparagus can also be pickled and stored for several years. Some brands label shoots prepared in this way as "marinated".
Stem thickness indicates the age of the plant, with the thicker stems coming from older plants. Older, thicker stalks can be woody, although peeling the skin at the base removes the tough layer. Peeled asparagus will however poach much faster. The bottom portion of asparagus often contains sand and dirt, so thorough cleaning is generally advised before cooking.