I just realized I never checked back on that post about worm farming. I think what the PP meant about it not being worth it to plant directly in the worm castings is that it takes a long time to get a good amount. Also, from what I've heard, worm castings can be such a potent fertilizer that they can burn the plants if you use them alone. I mixed mine into my compost and had the best tomatoes on the block this year. I'd also say to do what the PP did and mix some worm castings with water to make a "worm tea" (yum! lol) and use it to water the plants. This will make your castings go farther.
Let us know if you decide to dive in!