Alex the dog,
Nice name...those were awesome commercials.
In the fall my asparagus gets covered up with a thick layer of leaves. When it thaws I’ll pull some, but not all, of the leaves back leaving a thin layer. The asparagus will poke through that thin layer. You don’t want to leave them too thick or it won’t work as well. For me it keeps the weeds at bay long enough for the asparagus to pretty much choke anything else out. One thing you don’t want to do is clear cut the dried up stems in the fall. Leave them until spring and cut them out then. If you do it in the fall you’ll increase the possibility of disease and asparagus beetle infestations to your established patch.
While this isn't a complete cure, I burn my patch in the spring. Then I ligthtly hoe the ground and apply Preen and fertilizer. This is done as soon as the ground unthaws in the spring and before anything is growing. It works ok, but isn't a complete removal of the grass/weeds. I just pull them as I pick during the season as best as I can. After I'm done picking for the year I let the asparagus go to seed and then carefully treat the areas between the rows with RoundUp. My asparagus was planted in rows, so that helps, but it is spreading and I'm going to have to look at something else soon. Keep in mind that treating with the Preen is most likely going to stop any Aspargus seed from the year before from sprouting. I've been picking a handful everyday for the last week and a half so it is working ok.
For those of you with garden patches what do you do for weed control? I’ve heard about salting at anytime or preemergent Roundup for the early grasses. I battle with grasses mid season and beyond. This year it looks especially bad.