Asparagus Ferns should be cleaned off the patch in the Fall each year!
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. 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 in order to minimize asparagus insect pests like asparagus beetles and pathogens that have been overwintering in the ferns.
Don’t till the ferns into the soil as it contributes relatively little organic matter and can create insect pest problems.