Hi Mari,

This is what the University of Minnesota says:

“The asparagus ferns gradually die in the late fall, turning brown by winter. As they die, they transport carbon and nutrients down to the roots for winter storage. The ferns must be removed every year once they are completely yellow or brown. Do not remove green ferns, as this decreases energy storage in the plants.

Remove ferns in the late fall or early spring. When possible, late fall is preferred, to eliminate insect pests that overwinter in the ferns. However, fall fern removal is rarely possible in Minnesota because the fields usually become covered in snow while the ferns are still green. Most Minnesota growers wait until spring to remove the ferns.

Remove ferns from the crowns by chopping, mowing or burning. In spring, it is best to remove them from the field and burn or compost them elsewhere to minimize asparagus insect pests like asparagus beetles and pathogens that have been overwintering in the ferns.”

Note that this was written for people who are growing fields of asparagus for commercial sale. Cut them down near ground level and remove them from your property.

Hope this helps!