You've given me very little to work with.  Growing conditions: sun or shade? clay soil or sand? Did you do a soil test? How did you plant the plants?  How did you manage them?  Water? Fertilizer? If you cut them back, when did you do that? When did you stop harvesting?  What did they look like before they died?

Here is a good primer on growing asparagus in Minnesota:
https://extension.umn.edu/vegetables/growing-asparagus

Thanks for your quick response.  The bed is in the sun almost all the time in sandy soil.  I watered it when the adjacent garden was sprinkled. I did not soil test.  4 years ago I worked the soil about 8” deep and mixed in compost. Then planted the roots an inch to inch and a half deep.  I took no cuttings for two years. Third year I took about three spears. Last year a meal for two.  I let them grow to thick fronds each year and cut the dead fronds back in the spring. I fertilize with 10-10-10 in spring and mid summer.  I never harvested after mid June. The fronds were brown and dead when I cut them back in early May.  I looked later for sprouts and found two about an inch long, curled and brownish green. Nothing else was evident of growth. The bed is bound by lawn, day lilies and a vegetable garden. I don’t use herbicides on my lawn.

I don't see anything in your narrative that looks like an obvious problem. When planting asparagus crowns (the most common way to plant it), dig a trench several inches deep, then plant in the trench and add soil to cover as the plants grow up.  Those instructions are in the primer link I sent.