Too bad they won't allow dynamite! The only other thing I can think of is to drive a wedge of some sort like a crow bar in with a hammer and then rock it around until you can get at shovel in to dig it out a little at a time, probably.
Granted it won't be easy. It might work better if you soak the area, but then of course you'll be working in mud. Maybe you can blast some dirt out underneath with a strong blast from the hose or maybe a pressure washer to expose the roots. I don't think any way will be easy. Unless you want to try a brush killer, something stronger then round up. Wish I could be of more help.

I wonder if Round Up would work...there are times when we're forced to use things we really don't want to use and this may be one of those times. Believe it or not I had some poison ivy in the monkey grass inside my pool cage and after years of not being allergic to it and pulling it out on a regular basis I finally built up enough antibodies to start having an allergic response...was forced to buy the Round Up Poison Ivy mix, so now I don't have to worry about it anymore ;-)

I'm monitoring this post to see if anyone comes up with a good kill plan. I've got it around the edges of the yard, really all along the perimeter. In one place, the puppy steps on it to get to a good view of the cats next door. I can report that a 75-pound puppy stepping all over it does not discourage it at all. Just kills everything else back there.

Karw, the best way to erradicate them is the crowning technigue. I used it on the ones the former owner of this hous left next to the sidewalk on the way to the door. They have not returned but it is work. Linda

So far, no easy means of dealing with this pretty weed. Best method and hands-on, seems to be initial removal of each plant's crown and all berries: with follow-up digging out.

An effective way of removing Asparagus fern (Asparagus densiflorus) by hand with minimal soil disturbance is by crowning.

The growing point of Asparagus fern is the crown, which is below the soil surface. The crowning technique is as follows:

Grab the stems and hold tightly so you can see the base of the plant (wear sturdy gloves).

Insert boning knife or trowel around the crown, going in at an angle to the base of the crown.

Cut through roots to remove the crown. Only the crown has to be removed to kill the plant.
Either remove the crown completely from the site or leave it where it has no contact with the ground (Remember to replace any soil that has been disturbed and put the existing mulch back over the site.)

The tubers of Asparagus fern are only for storing water and can be left in the ground

I had a big patch of it also, Once I was able to loosen it around the edges, I then rolled it up like a very heavy carpet. It was very hard and dirty work. I stuffed it into a lawn and leaf bag, it was so heavy, I could barely drag it to the curb.
So, SFH, are you saying the fern is not propagated by those tubers? The kids and I called them peanuts. We spent hours picking all of them up! I am pretty sure we got it all. But who knows it might come back to haunt me some more. - Sharon

Really? I've been assuming I had to dig up all their little tubers.

I could potentially accomplish this.

If I do this, and keep an eye on the sprays that come over from the neighbor's yard, and cut them before they fruit, would I actually get rid of it? I had pretty much given up on getting rid of it. But if I could get my yard down to just volunteers from the neighbor's yard, maybe I could get a handle on it.

I already patrol pretty aggressively for volunteers because my neighbors have brazilian pepper trees. For all the time they spend trimming their yard, I'd spend an afternoon cutting those damn things out.

hmmmm. gotta get out there with a knife and gloves.

Thanks for the comments and the advice. I'll try putting it to the knife and see if that works.

There are a million of the little round seeds; do you think using a pre-emergent like Preen would help prevent them from sprouting?

Round=up will eventually kill the plant if you apply several applications weekly and apply lots of patience. I assume that a good pre-emergent might work. It would be worth a try. You could always pla a Halloween party and have a scavenger hunt where the person who finds the most aspargus fern seeds wins? Hace a bon-fire and roast those babies