CoralReefs
Suburban baccy farmer
I am not sure I would want to start seed in worm castings. the very young sprouts do not seem to do well with fertilizers etc. I am not sure how the other things in worm castings might work for them though. YOu might germinate the seed and let them grow for a couple of weeks then transplant to pots with worm castings though.
That would be my suspicion as well. Then again, it never hurts to try it out with a few and see what happens. I think a lot of it would depend on the concentration of nutrients in the castings.