asparagus

I am going to set up a SFG for asparagus, laying the box over an old gardening spot, which has its share of weeds that can come up. Can and should I use a weed block underneath the box, with this type of plant? Also, are there any companion plants that can be interspersed in this bed, whether they be flowers, or other vegetables?

I've got a couple dozen crowns coming next month. It's my first time with asparagus. Parsley and asparagus are mutually beneficial in promoting one another's health and vigor. That's what I am going to use. Other companions are basil and tomatoes, but my source does not say why those are good. My source did not note if they had any enemies. I'm going to leave the bottom of the box open because asparagus has very long taproots, I think something like 4 feet or more. Also do get the weeds out of there, asp does not compete with them.

I had reasonably good luck with a bed of strawberries + asparagus when I lived in Southern California.

Now that I have more space and sunlight, I'll be dedicating one 4'x2' x 12" to asparagus. Although I know from experience that this crop does okay in 6" of MM, I thought I'd give it some extra leg-room. I've read that asparagus taproots can grow to 12'! In fact, some of mine spread into adjacent areas, and I inadvertently hacked off some roots while preparing another bed.

12 ft. Wow. I've read 4 to 5 feet roots are possible. I've got a 12 inch deep bed too.

These are good tips. I think I can squeeze in a tomato plant or two and basil works for me. I guess I will try to till the old spot before I put the box on it. Thanks

Onions, Chives, etc. don't "companion" well with Asparagus. I don't recall the source or why, though. I just remember reading about it & wondering if my chives were too close to my Asparagus & moving my chives away just in case.

I agree with all the above.
Good guys: basil, parsley, tomatoes and even the flower calendula.
Bad Guys: Any of the onion family; chives, leeks, shallots, garlic.
They have terribly long tap roots so I would layer beneath the box with 3 or 4 sheets of newspaper to halt any weed seeds and keep them dormant, before filling the bed. The newspaper will eventually disintegrate but by then hopefully the weed seeds will no longer be active and not pop thru but the asparagus can burrow in.
Remember, make a trench and plant them. Fill the trench as the plant grows. Do it at least a couple times. Some varieties (Jersey Knight is one) only need to be planted about 6" deep and covered with 2" of soil. Then cover twice with 2" more of soil as the plant grows.
If you must weed, be very careful around asparagus. Just pull any weeds while small instead of using a cultivator.
Don't harvest any the first year or two so the roots can grow stronger.
Good luck and you'll soon be enjoying fresh asparagus for 15-20 years.