Here are some options you could use, depending on the context:
* A bunch of asparagus (This is the most common and straightforward option.)
* A spear of asparagus (If you are referring to individual stalks)
* A bed of asparagus (If you are referring to a field or garden where asparagus is growing)
* A crop of asparagus (If you are talking about a harvest)
Ultimately, the best option depends on what you want to emphasize.