
Keeping perennial weeds out of asparagus beds is a legendary problem, but modern science has made it easier. If your asparagus bed is over-run with weed or couch grass, go over it with a glyphosate weedkiller like Roundup WHILE THE ASPARAGUS IS DORMANT. As long as the asparagus is completely underground and not beginning to shoot, the weedkiller won't harm it. Then give it a nice thick mulch with something nourishing - both well-rotted manure and spent mushroom compost are good.