MrSterlingedit: Also I have a bag of Espoma Organics "Rock Phosphate", what's the deal on that? I thought I've read talk about rock phosphate being rather non-ecofriendly in its production, and I haven't heard anyone mention it in their soil amendments. Seems that much like greensand, if you were recycling your soil it might start to have a positive effect after a few grows.
I don't won't discuss mined phosphate any more - too much emotion and worse.
See what you can garner from this paper from the University of Minnesota - Understanding Phosphorus Fertilizers