let it grow exactly as it is, it will grow quite tall (3 - 4 foot) and develop little red berries in autumn, and this foliage will die off during the winter.
when it`s dead simply remove it and compost it.
then wait until next May, in the 3`rd year you can take a few sprigs (not all of them) and let the cycle continue again.
spare a thought for me, I started mine of from Seed not the crowns, it takes 7 years before you can start eating it!
happily next year will be that 7`th year :)
if ever you get change to go to the beach, get hold of plenty seaweed, and dry it as best you can and bring it home with you, when it`s totally dry, crush it up and sprinkle that on the asparagus bed, they love it.
So long and Thanks for all the Fish ;)