Experts and BHG readers answer.
Getting Rid of Grass
Thanks for writing. Your best bet would be to cut the grass as low as you can, then cover it with several sheets of newspaper and then cover that with a couple of inches of mulch or compost. Then dig a perimeter around your asparagus bed and edge that so you don't have grass creeping back in.
Some grass may start to grow through the mulch --- if that happens, pull it as soon as you notice it.
---Justin, Senior Garden Editor, BHG.com"