I think your friend might have to use a different kind of worm, not EF.

What about veggies that do well in an aquaponic system? They are in water all the time and get very good results. I think a great experiment would be to have a raised bin lined with plastic or a rubber pond liner filled with bedding, manure and compost worms kept really, really wet.

Bentley, over at redwormcomposting.com has tried this and found that it did not work well. It seems that the conditions in which plants grow well are not the same conditions in which worms grow well. OTOH, he has grown worms in a trench near the root zone, and had great results.

I have had EF in my square foot garden raised beds since March of this year. I just added a handful in each box. Every so often I put some food buried in the corner to keep them happy. I've had over 100 degree days and they seem to be multiplying. There is a post on Square Foot Garden right now that talks about the difference in his soil after including worms. It starts "Second year RB/SFG core sample". Also at Growing Power they add worms to all their growing containers. I have mild winters here and I'll see if they make it through the winter.

Thanks for the comments, folks. I will need to do some more research on this. Bentley sent me an e-mail about his pole beans in boxes with worms, & those beans turned out real well.
I am also looking into some "Alabama Jumpers" as candidates for the raised beds instead of the EFs. It would be great to have it all in place for next spring.